[ { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/bqdrk-2kk46", "eprint_status": "archive", "datestamp": "2023-10-19 18:50:00", "lastmod": "2023-10-19 18:50:00", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Horton-Forrest", "name": { "family": "Horton", "given": "F." }, "orcid": "0000-0001-9524-8874" }, { "id": "Asimow-P-D", "name": { "family": "Asimow", "given": "P. D." }, "orcid": "0000-0001-6025-8925" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Curtice-John", "name": { "family": "Curtice", "given": "J." }, "orcid": "0000-0003-4029-8916" }, { "id": "Kurz-Mark-D", "name": { "family": "Kurz", "given": "M. D." }, "orcid": "0000-0003-1745-2356" }, { "id": "Blusztajn-Jerzy", "name": { "family": "Blusztajn", "given": "J." }, "orcid": "0000-0002-5475-1948" }, { "id": "Biasi-Joseph-A", "name": { "family": "Biasi", "given": "J. A." }, "orcid": "0000-0003-1196-7877" }, { "id": "Boyes-Xenia-M", "name": { "family": "Boyes", "given": "X. M." }, "orcid": "0000-0002-6607-9757" } ] }, "title": "Highest terrestial \u00b3He/\u2074He credibly from the core", "ispublished": "pub", "full_text_status": "public", "keywords": "Multidisciplinary", "note": "
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
\n\nM. Mahy of Parks Canada Nunavut Field Unit assisted with fieldwork planning. V. Hooten performed mineral separation. N. Chatterjee carried out electron microprobe analyses. This research was funded by the National Science Foundation (award number 1911699). The Woods Hole Oceanographic Institution Andrew W. Mellon Foundation Endowed Fund for Innovative Research and a National Geographic Society grant (CP4-144R-18) supported fieldwork activities.
\n\nF.H.: conceptualization, methodology, investigation, writing\u2014original draft, visualization, supervision, and funding acquisition. P.D.A.: conceptualization, investigation, resources, writing\u2014review and editing, supervision, and funding acquisition. K.A.F.: conceptualization, methodology, investigation, resources, writing\u2014review and editing, supervision, and funding acquisition. J.C.: methodology and investigation. M.D.K.: resources, methodology, writing\u2014review and editing, and supervision. J.B.: methodology, investigation, resources, writing\u2014review and editing. J.A.B.: investigation. X.M.B.: formal analysis and investigation.
\n\nAll data are available in the paper, the supplementary materials and on EarthChem (https://doi.org/10.26022/IEDA/112776).
\n\nThe authors declare no competing interests.
", "abstract": "The observation that many lavas associated with mantle plumes have higher \u00b3He/\u2074He ratios than the upper convecting mantle underpins geophysical, geodynamic and geochemical models of Earth's deep interior. High \u00b3He/\u2074He ratios are thought to derive from the solar nebula or from solar-wind-irradiated material that became incorporated into Earth during early planetary accretion. Traditionally, this high-\u00b3He/\u2074He component has been considered intrinsic to the mantle, having avoided outgassing caused by giant impacts and billions of years of mantle convection1,2,3,4. Here we report the highest magmatic \u00b3He/\u2074He ratio(67.2\u2009\u00b1\u20091.8 times the atmospheric ratio) yet measured in terrestrial igneous rocks, in olivines from Baffin Island lavas. We argue that the extremely high-\u00b3He/\u2074He helium in these lavas might derive from Earth's core5,6,7,8,9. The viability of the core hypothesis relaxes the long-standing constraint\u2014based on noble gases in lavas associated with mantle plumes globally\u2014that volatile elements from the solar nebula have survived in the mantle since the early stages of accretion.
", "date": "2023-10-18", "date_type": "published", "publication": "Nature", "publisher": "Nature Publishing Group", "issn": "0028-0836", "official_url": "https://authors.library.caltech.edu/records/bqdrk-2kk46", "funders": { "items": [ { "grant_number": "EAR-1911699" }, {}, {}, { "grant_number": "CP4-144R-18" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/s41586-023-06590-8", "primary_object": { "basename": "41586_2023_6590_Fig6_ESM.jpg", "url": "https://authors.library.caltech.edu/records/bqdrk-2kk46/files/41586_2023_6590_Fig6_ESM.jpg" }, "related_objects": [ { "basename": "41586_2023_6590_Fig7_ESM.jpg", "url": "https://authors.library.caltech.edu/records/bqdrk-2kk46/files/41586_2023_6590_Fig7_ESM.jpg" }, { "basename": "41586_2023_6590_Fig8_ESM.jpg", "url": "https://authors.library.caltech.edu/records/bqdrk-2kk46/files/41586_2023_6590_Fig8_ESM.jpg" }, { "basename": "41586_2023_6590_Fig9_ESM.jpg", "url": "https://authors.library.caltech.edu/records/bqdrk-2kk46/files/41586_2023_6590_Fig9_ESM.jpg" }, { "basename": "41586_2023_6590_MOESM1_ESM.xlsx", "url": "https://authors.library.caltech.edu/records/bqdrk-2kk46/files/41586_2023_6590_MOESM1_ESM.xlsx" }, { "basename": "41586_2023_6590_Tab1_ESM.jpg", "url": "https://authors.library.caltech.edu/records/bqdrk-2kk46/files/41586_2023_6590_Tab1_ESM.jpg" }, { "basename": "41586_2023_6590_Fig4_ESM.jpg", "url": "https://authors.library.caltech.edu/records/bqdrk-2kk46/files/41586_2023_6590_Fig4_ESM.jpg" }, { "basename": "41586_2023_6590_Fig5_ESM.jpg", "url": "https://authors.library.caltech.edu/records/bqdrk-2kk46/files/41586_2023_6590_Fig5_ESM.jpg" } ], "resource_type": "article", "pub_year": "2023", "author_list": "Horton, F.; Asimow, P. D.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/stteb-5r486", "eprint_id": 122479, "eprint_status": "archive", "datestamp": "2023-08-22 21:28:10", "lastmod": "2023-11-07 19:34:16", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sharma-Sunanda", "name": { "family": "Sharma", "given": "Sunanda" }, "orcid": "0000-0001-8822-7960" }, { "name": { "family": "Roppel", "given": "Ryan D." }, "orcid": "0000-0002-1782-1388" }, { "name": { "family": "Murphy", "given": "Ashley E." }, "orcid": "0000-0003-2533-6224" }, { "name": { "family": "Beegle", "given": "Luther W." }, "orcid": "0000-0002-4944-4353" }, { "name": { "family": "Bhartia", "given": "Rohit" }, "orcid": "0000-0002-1434-7481" }, { "name": { "family": "Steele", "given": "Andrew" }, "orcid": "0000-0001-9643-2841" }, { "name": { "family": "Razzell Hollis", "given": "Joseph" }, "orcid": "0000-0002-6239-694X" }, { "name": { "family": "Siljestr\u00f6m", "given": "Sandra" }, "orcid": "0000-0002-4975-6074" }, { "name": { "family": "McCubbin", "given": "Francis M." }, "orcid": "0000-0002-2101-4431" }, { "name": { "family": "Asher", "given": "Sanford A." }, "orcid": "0000-0003-1061-8747" }, { "id": "Abbey-William-J", "name": { "family": "Abbey", "given": "William J." } }, { "id": "Allwood-Abigail-C", "name": { "family": "Allwood", "given": "Abigail C." } }, { "name": { "family": "Berger", "given": "Eve L." }, "orcid": "0000-0002-9902-439X" }, { "name": { "family": "Bleefeld", "given": "Benjamin L." } }, { "name": { "family": "Burton", "given": "Aaron S." }, "orcid": "0000-0002-1194-4336" }, { "name": { "family": "Bykov", "given": "Sergei V." }, "orcid": "0000-0002-6161-0027" }, { "id": "Cardarelli-Emily-L", "name": { "family": "Cardarelli", "given": "Emily L." }, "orcid": "0000-0001-5451-2309" }, { "name": { "family": "Conrad", "given": "Pamela G." }, "orcid": "0000-0001-5724-3343" }, { "name": { "family": "Corpolongo", "given": "Andrea" }, "orcid": "0000-0002-8623-358X" }, { "name": { "family": "Czaja", "given": "Andrew D." }, "orcid": "0000-0002-2450-0734" }, { "id": "DeFlores-Lauren-P", "name": { "family": "DeFlores", "given": "Lauren P." } }, { "name": { "family": "Edgett", "given": "Kenneth" }, "orcid": "0000-0001-7197-5751" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "name": { "family": "Fornaro", "given": "Teresa" }, "orcid": "0000-0001-7705-9658" }, { "name": { "family": "Fox", "given": "Allison C." }, "orcid": "0000-0002-5952-4170" }, { "name": { "family": "Fries", "given": "Marc D." }, "orcid": "0000-0003-2761-6692" }, { "name": { "family": "Harker", "given": "David" }, "orcid": "0000-0001-6397-9082" }, { "name": { "family": "Hickman-Lewis", "given": "Keyron" }, "orcid": "0000-0001-8014-233X" }, { "name": { "family": "Huggett", "given": "Joshua" } }, { "name": { "family": "Imbeah", "given": "Samara" }, "orcid": "0000-0003-2921-1840" }, { "name": { "family": "Jakubek", "given": "Ryan S." }, "orcid": "0000-0001-7880-9422" }, { "name": { "family": "Kah", "given": "Linda C." }, "orcid": "0000-0001-7172-2033" }, { "name": { "family": "Lee", "given": "Carina" }, "orcid": "0000-0001-8151-3438" }, { "id": "Liu-Yang-JPL", "name": { "family": "Liu", "given": "Yang" } }, { "name": { "family": "Magee", "given": "Angela" }, "orcid": "0000-0001-5414-8519" }, { "name": { "family": "Minitti", "given": "Michelle" }, "orcid": "0000-0003-4715-4544" }, { "id": "Moore-Kelsey-R", "name": { "family": "Moore", "given": "Kelsey R." } }, { "name": { "family": "Pascuzzo", "given": "Alyssa" }, "orcid": "0000-0003-0180-1371" }, { "name": { "family": "Rodriguez Sanchez-Vahamonde", "given": "Carolina" }, "orcid": "0000-0002-0390-5054" }, { "name": { "family": "Scheller", "given": "Eva L." }, "orcid": "0000-0002-9981-5802" }, { "name": { "family": "Shkolyar", "given": "Svetlana" }, "orcid": "0000-0001-9641-1071" }, { "id": "Stack-Kathryn-M", "name": { "family": "Stack", "given": "Kathryn M." }, "orcid": "0000-0003-3444-6695" }, { "id": "Steadman-Kim", "name": { "family": "Steadman", "given": "Kim" }, "orcid": "0000-0002-3192-0489" }, { "id": "Tuite-Michael", "name": { "family": "Tuite", "given": "Michael" }, "orcid": "0000-0002-7352-4556" }, { "id": "Uckert-Kyle", "name": { "family": "Uckert", "given": "Kyle" }, "orcid": "0000-0002-0859-5526" }, { "name": { "family": "Werynski", "given": "Alyssa" }, "orcid": "0000-0002-2264-3133" }, { "name": { "family": "Wiens", "given": "Roger C." }, "orcid": "0000-0002-3409-7344" }, { "name": { "family": "Williams", "given": "Amy J." }, "orcid": "0000-0001-6299-0845" }, { "name": { "family": "Winchell", "given": "Katherine" } }, { "name": { "family": "Kennedy", "given": "Megan R." }, "orcid": "0000-0001-5076-6395" }, { "name": { "family": "Yanchilina", "given": "Anastasia" }, "orcid": "0000-0003-3782-6343" } ] }, "title": "Diverse organic-mineral associations in Jezero crater, Mars", "ispublished": "pub", "full_text_status": "public", "keywords": "Multidisciplinary", "note": "\u00a9 The Author(s) 2023. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. \n\nWe acknowledge the entire Mars 2020 Perseverance rover team. The research described in this paper was partially carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration under grant award no. 80NM0018D0004. The SHERLOC team is supported by the NASA Mars 2020 Phase E funds to the SHERLOC investigation. S. Siljestr\u00f6m acknowledges funding from the Swedish National Space Agency (contract nos. 137/19 and 2021-00092). T.F. acknowledges funding from Italian Space Agency (ASI) grant agreement no. ASI/INAF no. 2017-48-H-0. S. Shkolyar acknowledges support from NASA under grant award no. 80GSFC21M0002. \n\nData availability: The data used for this study are released on the Planetary Data System (PDS) at https://pds.nasa.gov/. Data from the SHERLOC instrument are accessible at https://pds-geosciences.wustl.edu/missions/mars2020/sherloc.htm. Spectral data are organized by sol number and accessible in csv format at https://pds-geosciences.wustl.edu/m2020/urn-nasa-pds-mars2020_sherloc/data_processed/. Fundamental data record image data acquired by the ACI are organized by sol number and accessible in IMG format at https://pds-imaging.jpl.nasa.gov/data/mars2020/mars2020_imgops/data_aci_imgops/sol/. Fundamental data record image data acquired by the WATSON are organized by sol number and accessible in IMG format at https://pds-imaging.jpl.nasa.gov/data/mars2020/mars2020_imgops/data_watson_imgops/sol/. \n\nCode availability: All code used for image and data processing in this manuscript uses open-source libraries or previously published methods described herein. The code for ACI colorization is available under the Apache 2.0 licence at https://github.com/nasa-jpl/ACI-colorization. Loupe software is open source under the Apache 2.0 licence and available at https://github.com/nasa/Loupe. \n\nThese authors contributed equally: Sunanda Sharma, Ryan D. Roppel. \n\nContributions: S.S. and R.D.R. contributed equally to data analysis, drafting the manuscript and figures with substantial contributions from A.E.M. and A.S. A.E.M., R.B., A.S., J.R.H., S.V.B., A.C. and R.S.J. helped in data analysis and interpretation. A.E.M., L.W.B., R.B., A.C., A.S., W.J.A., B.L.B., E.L.C., P.G.C., A.D.C., K.E., A.C.F., D.H., J.H., S.I., L.C.K., C.L., A.M., M.M., A.P., C.R., A.W., R.C.W. A.J.W., K.W., M.W. and A.Y. helped with M2020 surface operations. L.W.B. and R.B. are the former principal investigator and deputy investigator, respectively, of the SHERLOC instrument. M.M. is the current interim principal investigator of the SHERLOC instrument and K.U. is the current deputy investigator. K.A.F. and K.M.S. are the project scientist and deputy project scientists, respectively, of the M2020 mission. All authors reviewed and edited the manuscript before submission. \n\nThe authors declare no competing interests.\n\nPublished - s41586-023-06143-z.pdf
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", "abstract": "The presence and distribution of preserved organic matter on the surface of Mars can provide key information about the Martian carbon cycle and the potential of the planet to host life throughout its history. Several types\u00a0of organic molecules have been previously detected in Martian meteorites1 and at Gale crater, Mars. Evaluating the diversity and detectability of organic matter elsewhere on Mars is important for understanding the extent and diversity of Martian surface processes and the potential availability of carbon sources. Here we report the detection of Raman and fluorescence spectra consistent with several species of aromatic organic molecules in the M\u00e1az and S\u00e9\u00edtah formations within the Crater Floor sequences of Jezero crater, Mars. We report specific fluorescence-mineral associations consistent with many classes of organic molecules occurring in different spatial patterns within these compositionally distinct formations, potentially indicating different fates of carbon across environments. Our findings suggest there may be a diversity of aromatic molecules prevalent on the Martian surface, and these materials persist despite exposure to surface conditions. These potential organic molecules are largely found within minerals linked to aqueous processes, indicating that these processes may have had a key role in organic synthesis, transport or preservation.", "date": "2023-07-27", "date_type": "published", "publication": "Nature", "volume": "619", "number": "7971", "publisher": "Nature Publishing Group", "pagerange": "724-732", "id_number": "CaltechAUTHORS:20230725-857223000.52", "issn": "0028-0836", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230725-857223000.52", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech", "grant_number": "80NM0018D0004" }, { "agency": "Swedish National Space Agency", "grant_number": "137/19" }, { "agency": "Swedish National Space Agency", "grant_number": "2021-00092" }, { "agency": "Agenzia Spaziale Italiana (ASI)", "grant_number": "2017-48-H.0" }, { "agency": "NASA", "grant_number": "80GSFC21M0002" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/s41586-023-06143-z", "pmcid": "PMC10371864", "primary_object": { "basename": "s41586-023-06143-z.pdf", "url": "https://authors.library.caltech.edu/records/stteb-5r486/files/s41586-023-06143-z.pdf" }, "related_objects": [ { "basename": "41586_2023_6143_Fig7_ESM.webp", "url": "https://authors.library.caltech.edu/records/stteb-5r486/files/41586_2023_6143_Fig7_ESM.webp" }, { "basename": "41586_2023_6143_Fig9_ESM.webp", "url": "https://authors.library.caltech.edu/records/stteb-5r486/files/41586_2023_6143_Fig9_ESM.webp" }, { "basename": "41586_2023_6143_Tab3_ESM.jpg", "url": "https://authors.library.caltech.edu/records/stteb-5r486/files/41586_2023_6143_Tab3_ESM.jpg" }, { "basename": "41586_2023_6143_Fig6_ESM.webp", "url": "https://authors.library.caltech.edu/records/stteb-5r486/files/41586_2023_6143_Fig6_ESM.webp" }, { "basename": "41586_2023_6143_Fig11_ESM.webp", "url": "https://authors.library.caltech.edu/records/stteb-5r486/files/41586_2023_6143_Fig11_ESM.webp" }, { "basename": "41586_2023_6143_Fig8_ESM.webp", "url": "https://authors.library.caltech.edu/records/stteb-5r486/files/41586_2023_6143_Fig8_ESM.webp" }, { "basename": "41586_2023_6143_Tab1_ESM.jpg", "url": "https://authors.library.caltech.edu/records/stteb-5r486/files/41586_2023_6143_Tab1_ESM.jpg" }, { "basename": "41586_2023_6143_Tab2_ESM.jpg", "url": "https://authors.library.caltech.edu/records/stteb-5r486/files/41586_2023_6143_Tab2_ESM.jpg" }, { "basename": "41586_2023_6143_Fig10_ESM.webp", "url": "https://authors.library.caltech.edu/records/stteb-5r486/files/41586_2023_6143_Fig10_ESM.webp" } ], "resource_type": "article", "pub_year": "2023", "author_list": "Sharma, Sunanda; Roppel, Ryan D.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/6wmh8-b7g21", "eprint_id": 122193, "eprint_status": "archive", "datestamp": "2023-08-22 21:23:40", "lastmod": "2023-10-20 19:05:52", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Swindle-Carl", "name": { "family": "Swindle", "given": "Carl" }, "orcid": "0000-0002-8706-9398" }, { "id": "Clark-Doug", "name": { "family": "Clark", "given": "Doug" }, "orcid": "0000-0001-9043-0730" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Helium isotope evidence for mixing of mantle-derived fluids and deeply penetrating surface waters in an obducted peridotite massif", "ispublished": "pub", "full_text_status": "public", "keywords": "Geochemistry and Petrology", "note": "\u00a9 2023 Elsevier. \n\nWe are grateful to Sarah Francis and Basil Tikoff for providing samples and Jonathan Treffkorn and Frank Pavia for help with analytical work. We acknowledge the Water and Environment Lab at Caltech for providing the analytical facilities to measure U and Th. We thank George Rossman for guidance associated with Raman spectroscopy. We thank Jeffery Catalano, Junju Yamamoto and the anonymous reviewers for the constructive feedback. We appreciate Chi Ma's assistance with the scanning electron microscope, and Claire Bucholz for time on the petrographic microscope. We recognize Lillian Adriana Pi\u00f1a Paez from California Institute of Technology for assistance with ArcGIS software. This work was partially supported by National Science Foundation Graduate Research Fellowship Grant DGE\u20101745301. \n\nThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\n\nSupplemental Material - 1-s2.0-S0016703723002351-mmc1.pdf
", "abstract": "We measured He and Ar in fresh peridotites from the Twin Sisters massif, Washington USA. \u00b3He/\u2074He ratios measured on >35 samples are highly variable (\u223c0.8 to \u223c6 times the atmospheric ratio, RA). Step-heating of a subset of these samples in every case reveals a low \u00b3He/\u2074He component (\u223c1 R_A) released at <1000 \u00b0C and a high \u00b3He/\u2074He component (>3 R_A) above that temperature, but these components are not effectively isolated by crushing and powder fusion analysis. He-Ar systematics indicate an intimate association of two fluid-inclusion hosted components in the peridotites. The first is a \u223c6 R_A mantle component that is released at higher temperatures during step heating and is more abundant in dunite bands than surrounding harzburgites. The second component, released at low temperatures, has a \u00b3He/\u2074He ratio of 1.0 \u00b1 0.5 R_A, atmospheric \u2074\u2070Ar/\u00b3\u2076Ar, and \u2074He/\u2074\u2070Ar far above atmospheric. It appears to be a mixture of mantle and radiogenic He sources introduced during obduction-related serpentinization, sometimes invisible, by surface-derived waters enriched with deeply-sourced helium.\nThese data indicate that mantle noble gas signatures can be retained in lithospheric peridotites against both diffusive loss and radiogenic ingrowth over at least 10\u2078 year timescales, likely due to concentration and immobilization of He in fluid inclusions. However, the mantle signature can be greatly modified by pervasive and potentially cryptic fluid alteration during emplacement.", "date": "2023-07-15", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "353", "publisher": "Elsevier", "pagerange": "45-60", "id_number": "CaltechAUTHORS:20230710-599244800.3", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230710-599244800.3", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF Graduate Research Fellowship", "grant_number": "DGE\u20101745301" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2023.05.015", "primary_object": { "basename": "1-s2.0-S0016703723002351-mmc1.pdf", "url": "https://authors.library.caltech.edu/records/6wmh8-b7g21/files/1-s2.0-S0016703723002351-mmc1.pdf" }, "resource_type": "article", "pub_year": "2023", "author_list": "Swindle, Carl; Clark, Doug; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/zvkwb-erq25", "eprint_id": 118295, "eprint_status": "archive", "datestamp": "2023-08-22 18:26:26", "lastmod": "2023-10-24 23:16:30", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Scheller-Eva-L", "name": { "family": "Scheller", "given": "Eva L." }, "orcid": "0000-0002-9981-5802" }, { "id": "Razzell-Hollis-Joseph", "name": { "family": "Razzell Hollis", "given": "Joseph" }, "orcid": "0000-0002-6239-694X" }, { "id": "Cardarelli-Emily-L", "name": { "family": "Cardarelli", "given": "Emily L." }, "orcid": "0000-0001-5451-2309" }, { "name": { "family": "Steele", "given": "Andrew" }, "orcid": "0000-0001-9643-2841" }, { "id": "Beegle-Luther-W", "name": { "family": "Beegle", "given": "Luther W." }, "orcid": "0000-0002-4944-4353" }, { "name": { "family": "Bhartia", "given": "Rohit" }, 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"0000-0002-3409-7344" }, { "id": "Williford-Kenneth-H", "name": { "family": "Williford", "given": "Kenneth H." }, "orcid": "0000-0003-0633-408X" }, { "name": { "family": "Winchell", "given": "Kathrine" } }, { "name": { "family": "Wogsland", "given": "Brittan" }, "orcid": "0000-0002-7829-5094" }, { "name": { "family": "Yanchilina", "given": "Anastasia" }, "orcid": "0000-0003-3782-6343" }, { "name": { "family": "Yingling", "given": "Rachel" }, "orcid": "0000-0001-7368-443X" }, { "name": { "family": "Zorzano", "given": "Maria-Paz" }, "orcid": "0000-0002-4492-9650" } ] }, "title": "Aqueous alteration processes in Jezero crater, Mars\u2014implications for organic geochemistry", "ispublished": "pub", "full_text_status": "public", "keywords": "Multidisciplinary", "note": "\u00a9 2022 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. \n\nWe thank the entire Perseverance rover team. The work described in this paper was partially carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. We thank K. Edgett for his contributions to the team and S. Le Mou\u00e9lic for helpful comments. We thank V. Chevrier and two anonymous reviewers for their improvements to the manuscript. \n\nE.L.S. was supported by a NASA Earth and Space Science Fellowship (NESSF) (grant 80NSSC18K1255). J.R.H. and A.C.F. were supported by a NASA Postdoctoral Program fellowship. E.L.S. J.R.H., A.S., L.W.B., R.B., B.L.E., P.G.C., M.F., F.M.M., and A.S.B. were supported by the NASA Mars 2020 Phase-E funds to the SHERLOC investigation. A.J.W. was supported by the NASA M2020 Participating Scientist Program. T.F. was supported by an Italian Space Agency grant (#2017-48-H.0). A.G.F was supported by the European Research Council Consolidator Grant (#818602). R.W. was funded by NASA contracts NNH15AZ25I and NNH13ZDA018O. S.S. was supported by the Swedish National Space Agency (contracts 137/19 and 2021-00092). K. H.-L. is funded by an Aurora Research Fellowship from the UK Space Agency (grant ST/V00560X/1). \n\nAuthor contributions: E.L.S. and J.R.H. contributed equally to data analysis. E.L.S. and J.R.H. wrote the manuscript with substantial contributions from A.S. and E.C. L.W.B. and R.B. are the principal and deputy investigators of the SHERLOC instrument. K.U. developed the Loupe software. P.C., S.Sha., B.L.E., W.J.A., S.A.A., E.L.B., B.L.B., A.S.B., S.V.B., L.D., D.M.F., T.F., A.C.F., M.F., K.H.-L., W.F.H., J.E.H., S.I., R.S.J., M.R.K., C.L., F.M.M., B.E.N., C.R.S.-V., R.D.R., S.Si., S.Shk., K.S., A.W., K.H.W., K.W., B.W., A.Y., and R.Y. are members of the SHERLOC science and operations teams, who participated in planning and carrying out SHERLOC data acquisitions, calibration, and processing during rover operations. The SHERLOC science team also provided laboratory measurements and data analysis and contributed to the writing of the initial manuscript. T.K., K.R.M., and Y.L. are members of the PIXL team, who assisted in paired SHERLOC and PIXL data analysis. K.C.B., O.B., T.B., A.J.B., E.L.C., A.G.F., K.A.F., L.C.K., P.K., L.M., J.I.N., M.S., M.A.S., S.K.S., D.L.S., J.I.S., R.J.S., K.M.S., B.P.W., A.J.W., R.C.W., and M.P.-Z. are members of the wider Perseverance rover science team; they contributed to planning the SHERLOC data acquisitions, participated in data interpretation, and/or assisted in revising the manuscript. \n\nData and materials availability: The data are available on the Planetary Data System, in the bundles for SHERLOC and WATSON (31), Mastcam-Z (32), Navcam and Hazcam (33), PIXL (34), and Supercam (35); the exact files we used are listed in the supplementary materials. The Loupe software is archived at Zenodo (36). Laboratory data used for the study are archived at Zenodo (37). \n\nWe declare no competing interests.", "abstract": "The Perseverance rover landed in Jezero crater, Mars, in February 2021. We used the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument to perform deep-ultraviolet Raman and fluorescence spectroscopy of three rocks within the crater. We identify evidence for two distinct ancient aqueous environments at different times. Reactions with liquid water formed carbonates in an olivine-rich igneous rock. A sulfate-perchlorate mixture is present in the rocks, which probably formed by later modifications of the rocks by brine. Fluorescence signatures consistent with aromatic organic compounds occur throughout these rocks and are preserved in minerals related to both aqueous environments.", "date": "2022-12-09", "date_type": "published", "publication": "Science", "volume": "378", "number": "6624", "publisher": "American Association for the Advancement of Science", "pagerange": "1105-1110", "id_number": "CaltechAUTHORS:20221212-615183000.3", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221212-615183000.3", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA Earth and Space Science Fellowship", "grant_number": "80NSSC18K1255" }, { "agency": "NASA Postdoctoral Program" }, { "agency": "Agenzia Spaziale Italiana (ASI)", "grant_number": "2017-48-H.0" }, { "agency": "European Research Council (ERC)", "grant_number": "818602" }, { "agency": "NASA", "grant_number": "NNH15AZ25I" }, { "agency": "NASA", "grant_number": "NNH13ZDA018O" }, { "agency": "Swedish National Space Agency", "grant_number": "137/19" }, { "agency": "Swedish National Space Agency", "grant_number": "2021-00092" }, { "agency": "United Kingdom Space Agency (UKSA)", "grant_number": "ST/V00560X/1" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.abo5204", "resource_type": "article", "pub_year": "2022", "author_list": "Scheller, Eva L.; Razzell Hollis, Joseph; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3jm6q-vz564", "eprint_id": 118387, "eprint_status": "archive", "datestamp": "2023-08-22 17:46:06", "lastmod": "2023-10-24 23:20:12", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Liu-Yang", "name": { "family": "Liu", "given": "Y." }, "orcid": "0000-0003-0308-0942" }, { "name": { "family": "Tice", "given": "M. 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M." }, "orcid": "0000-0002-8313-8595" }, { "name": { "family": "Sautter", "given": "V." }, "orcid": "0000-0002-4263-7558" }, { "name": { "family": "Shuster", "given": "D. L." }, "orcid": "0000-0003-2507-9977" }, { "name": { "family": "Siebach", "given": "K. L." }, "orcid": "0000-0002-6628-6297" }, { "name": { "family": "Simon", "given": "J. I." }, "orcid": "0000-0002-3969-8958" }, { "name": { "family": "Sinclair", "given": "K. P." }, "orcid": "0000-0001-6261-4591" }, { "id": "Stack-Kathryn-M", "name": { "family": "Stack", "given": "K. M." }, "orcid": "0000-0003-3444-6695" }, { "name": { "family": "Steele", "given": "A." }, "orcid": "0000-0001-9643-2841" }, { "id": "Tarnas-Jesse-D", "name": { "family": "Tarnas", "given": "J. D." }, "orcid": "0000-0002-6256-0826" }, { "name": { "family": "Tosca", "given": "N. J." }, "orcid": "0000-0003-4415-4231" }, { "id": "Uckert-Kyle", "name": { "family": "Uckert", "given": "K." }, "orcid": "0000-0002-0859-5526" }, { "name": { "family": "Udry", "given": "A." }, "orcid": "0000-0002-0074-8110" }, { "id": "Wade-Lawrence-A", "name": { "family": "Wade", "given": "L. A." }, "orcid": "0000-0001-8254-8181" }, { "name": { "family": "Weiss", "given": "B. P." }, "orcid": "0000-0003-3113-3415" }, { "name": { "family": "Wiens", "given": "R. C." }, "orcid": "0000-0002-3409-7344" }, { "id": "Williford-Kenneth-H", "name": { "family": "Williford", "given": "K. H." }, "orcid": "0000-0003-0633-408X" }, { "name": { "family": "Zorzano", "given": "M.-P." }, "orcid": "0000-0002-4492-9650" } ] }, "title": "An olivine cumulate outcrop on the floor of Jezero crater, Mars", "ispublished": "pub", "full_text_status": "public", "keywords": "Multidisciplinary", "note": "We are grateful to the Mars 2020 team members who participated in tactical and strategic science operations. Detailed comments by K. Edgett are greatly appreciated. Y.L. thanks L. P. Keszthelyi for the discussion about Earth and Mars lava flows; N. Williams for providing the base maps used in Fig. 1, A and C; and J. Bell for providing the image used in Fig. 1D.\n\nThe work described in this paper was partially carried out at the Jet Propulsion Laboratory (JPL), California Institute of Technology, under a prime contract with the National Aeronautics and Space Administration (80NM0018D0004). Y.L., M.M.T., A.C.A., J.A.H., C.M.H., S.D., R.P.H., J.H., D.A.K.P., J.L.J., K.A.F., K.M.S., J.D.T., B.C.C., E.L.C., K.M., L.W.B., L.A.W., J.P.G., A.H.T., B.H.N.H., J.R.J., W.T.E., S.M.M., A.G., R.C.W., and K.U. were supported by NASA grant 80NM0018D0004 through JPL. J.R.J. was also supported by ASU subcontract 15-707. R.C.W. was also supported by NASA grant NNH13ZDA018O for Supercam to LANL. D.T.F. was supported by Australian Research Council grant DE210100205. E.A.C. was supported by Canadian Space Agency grant 19PACOI0 and Natural Sciences and Engineering Research Council of Canada grant RGPIN-2021-02995. C.D.K.H., T.V.K., and M.E.S. were supported by Canadian Space Agency M2020 Participating Scientist grants. A.U., S.J.V., B.A.C., M.N., D.L.S., J.I.S., K.L.S., T.Bo., and B.P.W. were supported by NASA Mars 2020 Participating Scientist grants. The work of K.B., S.B., O.B., L.M., N.M., C.M.Q.-N., and V.S. on Mars 2020 was supported by CNES. K.H.-L. was supported by a UK Space Agency Aurora Research Fellowship. T.Bo. was supported by the Simons Foundation Collaboration on the Origins of Life. S.G. was supported by the UK Space Agency and the Royal Society (grant SRF\\R1\\21000106). A.G.F. was supported by the European Research Council CoG #818602.", "abstract": "The geological units on the floor of Jezero crater, Mars, are part of a wider regional stratigraphy of olivine-rich rocks, which extends well beyond the crater. We investigated the petrology of olivine and carbonate-bearing rocks of the S\u00e9\u00edtah formation in the floor of Jezero. Using multispectral images and x-ray fluorescence data, acquired by the Perseverance rover, we performed a petrographic analysis of the Bastide and Brac outcrops within this unit. We found that these outcrops are composed of igneous rock, moderately altered by aqueous fluid. The igneous rocks are mainly made of coarse-grained olivine, similar to some martian meteorites. We interpret them as an olivine cumulate, formed by settling and enrichment of olivine through multistage cooling of a thick magma body.", "date": "2022-09-30", "date_type": "published", "publication": "Science", "volume": "377", "number": "6614", "publisher": "American Association for the Advancement of Science", "pagerange": "1513-1519", "id_number": "CaltechAUTHORS:20221215-431170800.7", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221215-431170800.7", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech", "grant_number": "80NM0018D0004" }, { "agency": "JPL", "grant_number": "15-707" }, { "agency": "NASA", "grant_number": "NNH13ZDA018O" }, { "agency": "Australian Research Council", "grant_number": "DE210100205" }, { "agency": "Canadian Space Agency (CSA)", "grant_number": "19PACOI0" }, { "agency": "Natural Sciences and Engineering Research Council of Canada (NSERC)", "grant_number": "RGPIN-2021-02995" }, { "agency": "Canadian Space Agency (CSA)" }, { "agency": "Centre National d'\u00c9tudes Spatiales (CNES)" }, { "agency": "United Kingdom Space Agency (UKSA)" }, { "agency": "Simons Foundation" }, { "agency": "Royal Society", "grant_number": "SRF\\R1\\21000106" }, { "agency": "European Research Council (ERC)", "grant_number": "818602" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.abo2756", "resource_type": "article", "pub_year": "2022", "author_list": "Liu, Y.; Tice, M. M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/42j82-1hz60", "eprint_id": 118293, "eprint_status": "archive", "datestamp": "2023-08-22 17:45:58", "lastmod": "2023-10-24 23:16:25", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Stack-Kathryn-M", "name": { "family": "Stack", "given": "K. M." }, "orcid": "0000-0003-3444-6695" }, { "name": { "family": "Shuster", "given": "D. L." }, "orcid": "0000-0003-2507-9977" }, { "name": { "family": "Horgan", "given": "B. H. N." }, "orcid": "0000-0001-6314-9724" }, { "name": { "family": "Hurowitz", "given": "J. A." }, "orcid": "0000-0002-5857-8652" }, { "id": "Tarnas-Jesse-D", "name": { "family": "Tarnas", "given": "J. D." }, "orcid": "0000-0002-6256-0826" }, { "name": { "family": "Simon", "given": "J. 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W." } }, { "name": { "family": "Royer", "given": "C." }, "orcid": "0000-0002-5472-7235" }, { "name": { "family": "Sautter", "given": "V." }, "orcid": "0000-0002-4263-7558" }, { "name": { "family": "Schulte", "given": "M." }, "orcid": "0000-0001-8141-2020" }, { "name": { "family": "Sephton", "given": "M. A." }, "orcid": "0000-0002-2190-5402" }, { "name": { "family": "Sharma", "given": "S. K." }, "orcid": "0000-0002-5676-7572" }, { "id": "Sholes-Steven-F", "name": { "family": "Sholes", "given": "S. F." }, "orcid": "0000-0003-4854-1191" }, { "id": "Spanovich-Nicole", "name": { "family": "Spanovich", "given": "N." }, "orcid": "0000-0002-9584-5043" }, { "name": { "family": "St. Clair", "given": "M." }, "orcid": "0000-0002-7877-3148" }, { "name": { "family": "Tate", "given": "C. D." }, "orcid": "0000-0003-3467-0099" }, { "id": "Uckert-Kyle", "name": { "family": "Uckert", "given": "K." }, "orcid": "0000-0002-0859-5526" }, { "name": { "family": "VanBommel", "given": "S. J." }, "orcid": "0000-0002-6565-0827" }, { "name": { "family": "Yanchilina", "given": "A. G." }, "orcid": "0000-0003-3782-6343" }, { "name": { "family": "Zorzano", "given": "M.-P." }, "orcid": "0000-0002-4492-9650" } ] }, "title": "Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars", "ispublished": "pub", "full_text_status": "public", "keywords": "Multidisciplinary", "note": "Funding: This effort was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). K.A.F., K.M.S., J.D.T., V.Z.S., Y.L., J.N.M., A.C.A., Y.G., P.A.W., E.L.C., S.M.Mi., R.C.M., S.F.S., N.S., and K.U. were supported by NASA grant 80NM0018D0004 through JPL. D.T.F. was supported by Australian Research Council grant DE210100205. E.F.G. was supported by Canadian Space Agency grant 21EXPCOI1. E.A.C. was supported by Canadian Space Agency grant 19PACOI0 and Natural Sciences and Engineering Research Council of Canada grant RGPIN-2021-02995. C.D.K.H., T.V.K., and M.E.S. were supported by Canadian Space Agency M2020 Participating Scientist grants. M.M. was supported by the EU's Horizon 2020 research and innovation program under the Marie Sk\u0142odowska Curie grant 801199. G.P. was supported by ESA PRODEX Experiment Arrangement PEA 4000117520. V.D. was supported by Fonds pour la Recherche Scientifique. A.J.W., S.J.V., D.L.S., J.I.S., L.E.M., T.B., and E.M.H. were supported by NASA Mars 2020 Participating Scientist grants. T.B. was supported by the Simons Foundation Collaboration on the Origins of Life grant 327126. R.C.W. was supported by NASA Mars 2020 contracts NNH15AZ24I and NNH13ZDA018O for SuperCam and a LANL internal LDRD grant. S.K.S. was supported by JPL subcontract 1654163. S.G. was supported by the Royal Society Leverhulme Trust Senior Research Fellowship (SRF\\R1\\21000106) and the UK Space Agency Aurora program. M.-P.Z. was supported by the Spanish Ministry of Science and Innovation under grant PID2019-104205GB-C21. S.Si. was supported by the Swedish National Space Agency under contracts 137/19 and 2021-00092. K.B.K. was supported by the Carlsberg Foundation, grant CF19-0023. S.-E.H. was supported by the Research Council of Norway under grants 301238 and 309835. The work of O.B., A.C., O.F., L.M., N.M., C.Q.-N., P.B., K.B., B.C., E.C., E.D., T.F., J.L., S.L.M., S.M., P.-Y.M., P.P., C.P., P.C.P., C.R., and V.S. on Mars 2020 was supported by CNES. K.H.-L. was supported by a UK Space Agency Aurora Research Fellowship. M.A.S. was supported by UK Space Agency grants ST/V002732/1 and ST/V006134/1. J.F.B. was supported by NASA-JPL subcontract number 1511125. A.G.F. was supported by the European Research Council, Consolidator Grant 818602.", "abstract": "The Perseverance rover landed in Jezero crater, Mars, to investigate ancient lake and river deposits. We report observations of the crater floor, below the crater's sedimentary delta, finding that the floor consists of igneous rocks altered by water. The lowest exposed unit, informally named S\u00e9\u00edtah, is a coarsely crystalline olivine-rich rock, which accumulated at the base of a magma body. Magnesium-iron carbonates along grain boundaries indicate reactions with carbon dioxide\u2013rich water under water-poor conditions. Overlying S\u00e9\u00edtah is a unit informally named M\u00e1az, which we interpret as lava flows or the chemical complement to S\u00e9\u00edtah in a layered igneous body. Voids in these rocks contain sulfates and perchlorates, likely introduced by later near-surface brine evaporation. Core samples of these rocks have been stored aboard Perseverance for potential return to Earth.", "date": "2022-09-30", "date_type": "published", "publication": "Science", "volume": "377", "number": "6614", "publisher": "American Association for the Advancement of Science", "pagerange": "Art. No. eabo2196", "id_number": "CaltechAUTHORS:20221212-615014000.1", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221212-615014000.1", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech", "grant_number": "80NM0018D0004" }, { "agency": "Australian Research Council", "grant_number": "DE210100205" }, { "agency": "Canadian Space Agency (CSA)", "grant_number": "21EXPCOI1" }, { "agency": "Canadian Space Agency (CSA)", "grant_number": "19PACOI0" }, { "agency": "Natural Sciences and Engineering Research Council of Canada (NSERC)", "grant_number": "RGPIN-2021-02995" }, { "agency": "Marie Curie Fellowship", "grant_number": "801199" }, { "agency": "European Space Agency (ESA)", "grant_number": "PEA 4000117520" }, { "agency": "Fonds de la Recherche Scientifique (FNRS)" }, { "agency": "Simons Foundation", "grant_number": "327126" }, { "agency": "NASA", "grant_number": "NNH15AZ24I" }, { "agency": "NASA", "grant_number": "NNH13ZDA018O" }, { "agency": "Los Alamos National Laboratory" }, { "agency": "JPL", "grant_number": "1654163" }, { "agency": "Royal Society", "grant_number": "SRF\\R1\\21000106" }, { "agency": "Ministerio de Ciencia e Innovaci\u00f3n (MCINN)", "grant_number": "PID2019-104205GB-C21" }, { "agency": "Swedish National Space Agency", "grant_number": "137/19" }, { "agency": "Swedish National Space Agency", "grant_number": "2021-00092" }, { "agency": "Carlsberg Foundation", "grant_number": "CF19-0023" }, { "agency": "Research Council of Norway", "grant_number": "301238" }, { "agency": "Research Council of Norway", "grant_number": "309835" }, { "agency": "Centre National d'\u00c9tudes Spatiales (CNES)" }, { "agency": "United Kingdom Space Agency (UKSA)", "grant_number": "ST/V002732/1" }, { "agency": "United Kingdom Space Agency (UKSA)", "grant_number": "ST/V006134/1" }, { "agency": "JPL", "grant_number": "1511125" }, { "agency": "European Research Council (ERC)", "grant_number": "818602" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.abo2196", "resource_type": "article", "pub_year": "2022", "author_list": "Farley, K. A.; Stack, K. M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/d43wf-72196", "eprint_id": 115311, "eprint_status": "archive", "datestamp": "2023-08-22 17:35:36", "lastmod": "2023-10-24 16:25:26", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "da-Silva-Monteiro-Hevelyn", "name": { "family": "Monteiro", "given": "H. S." }, "orcid": "0000-0002-3797-1869" }, { "id": "Vasconcelos-Paulo-M-P", "name": { "family": "Vasconcelos", "given": "P. M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Mello-Claudio-T", "name": { "family": "Mello", "given": "C. L." } }, { "id": "Concei\u00e7\u00e3o-Fabiano-T", "name": { "family": "Concei\u00e7\u00e3o", "given": "F. T." } } ] }, "title": "Long-term vegetation-induced goethite and hematite dissolution-reprecipitation along the Brazilian Atlantic margin", "ispublished": "pub", "full_text_status": "public", "keywords": "Paleontology; Earth-Surface Processes; Ecology, Evolution, Behavior and Systematics; Oceanography", "note": "\u00a9 2022 Elsevier. \n\nReceived 23 November 2021, Revised 27 June 2022, Accepted 29 June 2022, Available online 2 July 2022. \n\nThis project was funded by the Australian Research Council (ARC Discovery DP160104988) grant to Paulo Vasconcelos and Kenneth Farley, National Science Foundation grant to KF, the S\u00e3o Paulo Research Foundation grant (Process n\u00b0: 2017/23577-2) to Fabiano Concei\u00e7\u00e3o, and the S\u00e3o Paulo Research Foundation scholarship (Process n\u00b0: 2018/00102-1) to Hevelyn Monteiro. We thank C\u00e9cile Gautheron and an anonymous reviewer for their constructive comments and suggestions.\n\nCRediT author statement. Hevelyn Monteiro: Conceptualization, Methodology, Investigation, Visualization, Writing \u2013 Original Draft; Paulo Vasconcelos: Conceptualization, Methodology, Funding acquisition, Resources, Writing \u2013 Review and Editing; Kenneth Farley: Methodology, Funding acquisition, Resources, Writing \u2013 Review and Editing; Claudio Mello: Resources, Writing \u2013 Review and Editing; Fabiano Concei\u00e7\u00e3o: Funding acquisition Resources, Writing \u2013 Review and Editing. \n\nThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\n\nSupplemental Material - 1-s2.0-S0031018222003078-mmc1.pdf
Supplemental Material - 1-s2.0-S0031018222003078-mmc2.pdf
Supplemental Material - 1-s2.0-S0031018222003078-mmc3.docx
Supplemental Material - 1-s2.0-S0031018222003078-mmc4.xlsx
Supplemental Material - 1-s2.0-S0031018222003078-mmc5.zip
Supplemental Material - 1-s2.0-S0031018222003078-mmc6.zip
", "abstract": "Distinctive sediments containing mostly quartz, kaolinite, and both detrital and authigenic hematite and goethite blanket ~5000 km of the Atlantic coast of Brazil from Rio de Janeiro all the way to the mouth of the Amazon River. The sediments represent a significant period of continental erosion followed by renewed weathering. Here we present (U-Th)/He ages of detrital and authigenic goethites and hematites collected from six weathering profiles in Esp\u00edrito Santo, southeastern Brazil. Detrital goethites are as old as ~26 Ma and the oldest authigenic hematite is ~20 Ma, suggesting that erosion, transportation, and deposition of the sediments occurred in the 26\u201320 Ma period. Intense post-depositional weathering and ferruginization of the sediments suggest that precipitation-dissolution-reprecipitation of iron oxides and oxyhydroxides were strongly controlled by biologically driven weathering reactions. (U-Th)/He geochronology of 158 grains of authigenic goethite and hematite precipitated during biologically mediated water-rock interaction yield 137 results in the 5\u20130.6 Ma period, suggesting that tropical climate and abundant vegetation dominated the coast of Esp\u00edrito Santo since the Pliocene.", "date": "2022-09-01", "date_type": "published", "publication": "Palaeogeography, Palaeoclimatology, Palaeoecology", "volume": "601", "publisher": "Elsevier", "pagerange": "Art. No. 111137", "id_number": "CaltechAUTHORS:20220705-671886000", "issn": "0031-0182", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220705-671886000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Australian Research Council", "grant_number": "DP160104988" }, { "agency": "NSF" }, { "agency": "Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de S\u00e3o Paulo (FAPESP)", "grant_number": "2017/23577-2" }, { "agency": "Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de S\u00e3o Paulo (FAPESP)", "grant_number": "2018/00102-1" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.palaeo.2022.111137", "primary_object": { "basename": "1-s2.0-S0031018222003078-mmc1.pdf", "url": "https://authors.library.caltech.edu/records/d43wf-72196/files/1-s2.0-S0031018222003078-mmc1.pdf" }, "related_objects": [ { "basename": "1-s2.0-S0031018222003078-mmc2.pdf", "url": "https://authors.library.caltech.edu/records/d43wf-72196/files/1-s2.0-S0031018222003078-mmc2.pdf" }, { "basename": "1-s2.0-S0031018222003078-mmc3.docx", "url": "https://authors.library.caltech.edu/records/d43wf-72196/files/1-s2.0-S0031018222003078-mmc3.docx" }, { "basename": "1-s2.0-S0031018222003078-mmc4.xlsx", "url": "https://authors.library.caltech.edu/records/d43wf-72196/files/1-s2.0-S0031018222003078-mmc4.xlsx" }, { "basename": "1-s2.0-S0031018222003078-mmc5.zip", "url": "https://authors.library.caltech.edu/records/d43wf-72196/files/1-s2.0-S0031018222003078-mmc5.zip" }, { "basename": "1-s2.0-S0031018222003078-mmc6.zip", "url": "https://authors.library.caltech.edu/records/d43wf-72196/files/1-s2.0-S0031018222003078-mmc6.zip" } ], "resource_type": "article", "pub_year": "2022", "author_list": "Monteiro, H. S.; Vasconcelos, P. M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/yymhf-wyt75", "eprint_id": 114272, "eprint_status": "archive", "datestamp": "2023-08-22 15:44:10", "lastmod": "2023-10-23 19:59:58", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Maurice-Sylvestre", "name": { "family": "Maurice", "given": "S." }, "orcid": "0000-0001-5702-8002" }, { "name": { "family": "Chide", "given": "B." }, "orcid": "0000-0002-5124-9119" }, { "name": { "family": "Murdoch", "given": "N." }, "orcid": "0000-0002-9701-4075" }, { "name": { "family": "Lorenz", "given": "R. D." }, "orcid": "0000-0001-8528-4644" }, { "name": { "family": "Mimoun", "given": "D." }, "orcid": "0000-0002-3427-2974" }, { "name": { "family": "Wiens", "given": "R. C." }, "orcid": "0000-0002-3409-7344" }, { "name": { "family": "Stott", "given": "A." } }, { "name": { "family": "Jacob", "given": "X." }, "orcid": "0000-0001-6718-4981" }, { "name": { "family": "Bertrand", "given": "T." }, "orcid": "0000-0002-2302-9776" }, { "name": { "family": "Montmessin", "given": "F." }, "orcid": "0000-0002-4187-1457" }, { "name": { "family": "Lanza", "given": "N. L." }, "orcid": "0000-0003-4445-7996" }, { "name": { "family": "Alvarez-Llamas", "given": "C." }, "orcid": "0000-0001-7793-7000" }, { "name": { "family": "Angel", "given": "S. M." } }, { "id": "Aung-M", "name": { "family": "Aung", "given": "M." } }, { "id": "Balaram-J-Bob", "name": { "family": "Balaram", "given": "J." } }, { "name": { "family": "Beyssac", "given": "O." } }, { "name": { "family": "Cousin", "given": "A." } }, { "name": { "family": "Delory", "given": "G." } }, { "name": { "family": "Forni", "given": "O." }, "orcid": "0000-0001-6772-9689" }, { "name": { "family": "Fouchet", "given": "T." }, "orcid": "0000-0001-9040-8285" }, { "name": { "family": "Gasnault", "given": "O." }, "orcid": "0000-0002-6979-9012" }, { "id": "Grip-Havard-F", "name": { "family": "Grip", "given": "H." } }, { "name": { "family": "Hecht", "given": "M." }, "orcid": "0000-0002-4114-4583" }, { "name": { "family": "Hoffman", "given": "J." } }, { "name": { "family": "Laserna", "given": "J." } }, { "name": { "family": "Lasue", "given": "J." }, "orcid": "0000-0001-9082-4457" }, { "id": "Maki-Justin-N", "name": { "family": "Maki", "given": "J." }, "orcid": "0000-0002-7887-0343" }, { "name": { "family": "McClean", "given": "J." } }, { "name": { "family": "Meslin", "given": "P.-Y." }, "orcid": "0000-0002-0703-3951" }, { "name": { "family": "Le Mou\u00e9lic", "given": "S." }, "orcid": "0000-0001-5260-1367" }, { "name": { "family": "Munguira", "given": "A." }, "orcid": "0000-0002-1677-6327" }, { "name": { "family": "Newman", "given": "C. E." }, "orcid": "0000-0001-9990-8817" }, { "name": { "family": "Rodr\u00edguez Manfredi", "given": "J. A." }, "orcid": "0000-0003-0461-9815" }, { "name": { "family": "Moros", "given": "J." } }, { "name": { "family": "Ollila", "given": "A." }, "orcid": "0000-0003-0479-9465" }, { "name": { "family": "Pilleri", "given": "P." }, "orcid": "0000-0003-4861-0476" }, { "name": { "family": "Schr\u00f6der", "given": "S." }, "orcid": "0000-0003-1870-3663" }, { "id": "de-la-Torre-Ju\u00e1rez-Manuel", "name": { "family": "de la Torre Ju\u00e1rez", "given": "M." }, "orcid": "0000-0003-1393-5297" }, { "id": "Tzanetos-Theodore", "name": { "family": "Tzanetos", "given": "T." } }, { "id": "Stack-Kathryn-M", "name": { "family": "Stack", "given": "K. M." }, "orcid": "0000-0003-3444-6695" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K." }, "orcid": "0000-0002-7846-7546" }, { "id": "Williford-Kenneth-H", "name": { "family": "Williford", "given": "K." }, "orcid": "0000-0003-0633-408X" }, { "name": { "family": "Wiens", "given": "R. C." }, "orcid": "0000-0002-3409-7344" }, { "name": { "family": "Acosta-Maeda", "given": "T." } }, { "name": { "family": "Anderson", "given": "R. B." } }, { "name": { "family": "Applin", "given": "D. M." } }, { "name": { "family": "Arana", "given": "G." } }, { "name": { "family": "Bassas-Portus", "given": "M." } }, { "name": { "family": "Beal", "given": "R." } }, { "name": { "family": "Beck", "given": "P." } }, { "name": { "family": "Benzerara", "given": "K." } }, { "name": { "family": "Bernard", "given": "S." } }, { "name": { "family": "Bernardi", "given": "P." } }, { "name": { "family": "Bosak", "given": "T." }, "orcid": "0000-0001-5179-5323" }, { "name": { "family": "Bousquet", "given": "B." } }, { "name": { "family": "Brown", "given": "A." } }, { "name": { "family": "Cadu", "given": "A." } }, { "name": { "family": "Ca\u00efs", "given": "P." } }, { "name": { "family": "Castro", "given": "K." } }, { "name": { "family": "Clav\u00e9", "given": "E." } }, { "name": { "family": "Clegg", "given": "S. M." }, "orcid": "0000-0002-0338-0948" }, { "name": { "family": "Cloutis", "given": "E." }, "orcid": "0000-0001-7301-0929" }, { "name": { "family": "Connell", "given": "S." } }, { "name": { "family": "Debus", "given": "A." } }, { "name": { "family": "Dehouck", "given": "E." }, "orcid": "0000-0002-1368-4494" }, { "name": { "family": "Delapp", "given": "D." }, "orcid": "0000-0002-2514-337X" }, { "name": { "family": "Donny", "given": "C." } }, { "name": { "family": "Dorresoundiram", "given": "A." } }, { "name": { "family": "Dromart", "given": "G." } }, { "name": { "family": "Dubois", "given": "B." } }, { "name": { "family": "Fabre", "given": "C." } }, { "name": { "family": "Fau", "given": "A." } }, { "id": "Fischer-W-W", "name": { "family": "Fischer", "given": "W." }, "orcid": "0000-0002-8836-3054" }, { "name": { "family": "Francis", "given": "R." } }, { "name": { "family": "Frydenvang", "given": "J." } }, { "name": { "family": "Gabriel", "given": "T." } }, { "name": { "family": "Gibbons", "given": "E." } }, { "name": { "family": "Gontijo", "given": "I." } }, { "name": { "family": "Johnson", "given": "J. R." } }, { "id": "Kalucha-Hemani", "name": { "family": "Kalucha", "given": "H." } }, { "name": { "family": "Kelly", "given": "E." } }, { "name": { "family": "Knutsen", "given": "E. W." } }, { "name": { "family": "Lacombe", "given": "G." } }, { "name": { "family": "Le Mou\u00e9lic", "given": "S." } }, { "name": { "family": "Legett", "given": "C." } }, { "name": { "family": "Leveille", "given": "R." } }, { "name": { "family": "Lewin", "given": "E." } }, { "name": { "family": "Lopez-Reyes", "given": "G." } }, { "name": { "family": "Lorigny", "given": "E." } }, { "name": { "family": "Madariaga", "given": "J. M." } }, { "name": { "family": "Madsen", "given": "M." } }, { "name": { "family": "Madsen", "given": "S." } }, { "name": { "family": "Mandon", "given": "L." } }, { "name": { "family": "Mangold", "given": "N." } }, { "name": { "family": "Mann", "given": "M." } }, { "name": { "family": "Manrique", "given": "J.-A." } }, { "name": { "family": "Martinez-Frias", "given": "J." } }, { "name": { "family": "Mayhew", "given": "L. E." } }, { "name": { "family": "McConnochie", "given": "T." } }, { "name": { "family": "McLennan", "given": "S. M." } }, { "name": { "family": "Melikechi", "given": "N." } }, { "name": { "family": "Meunier", "given": "F." } }, { "name": { "family": "Montagnac", "given": "G." } }, { "name": { "family": "Mousset", "given": "V." } }, { "name": { "family": "Nelson", "given": "T." } }, { "name": { "family": "Newell", "given": "R. T." } }, { "name": { "family": "Parot", "given": "Y." } }, { "name": { "family": "Pilorget", "given": "C." } }, { "name": { "family": "Pinet", "given": "P." } }, { "name": { "family": "Pont", "given": "G." } }, { "name": { "family": "Poulet", "given": "F." } }, { "name": { "family": "Quantin-Nataf", "given": "C." } }, { "name": { "family": "Quertier", "given": "B." } }, { "name": { "family": "Rapin", "given": "W." } }, { "name": { "family": "Reyes-Newell", "given": "A." } }, { "name": { "family": "Robinson", "given": "S." } }, { "name": { "family": "Rochas", "given": "L." } }, { "name": { "family": "Royer", "given": "C." } }, { "name": { "family": "Rull", "given": "F." } }, { "name": { "family": "Sautter", "given": "V." } }, { "name": { "family": "Sharma", "given": "S." } }, { "name": { "family": "Shridar", "given": "V." } }, { "name": { "family": "Sournac", "given": "A." } }, { "name": { "family": "Toplis", "given": "M." } }, { "name": { "family": "Torre-Fdez", "given": "I." } }, { "name": { "family": "Turenne", "given": "N." } }, { "name": { "family": "Udry", "given": "A." } }, { "name": { "family": "Veneranda", "given": "M." } }, { "name": { "family": "Venhaus", "given": "D." } }, { "name": { "family": "Vogt", "given": "D." } }, { "name": { "family": "Willis", "given": "P." } } ] }, "title": "In situ recording of Mars soundscape", "ispublished": "pub", "full_text_status": "public", "keywords": "Atmospheric dynamics; Characterization and analytical techniques; Multidisciplinary", "note": "\u00a9 The Author(s) 2022. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. \n\nReceived 07 December 2021; Accepted 23 March 2022; Published 01 April 2022. \n\nMany people helped with this project in addition to the co-authors, including hardware and operation teams, and we are most grateful for their support. This project was supported in the USA by NASA's Mars Exploration Program and in France is conducted under the authority of CNES. The work of A. Munguira is supported by grant PID2019-109467GB-I00 funded by MCIN/AEI/10.13039/501100011033. \n\nData availability: All acoustic data are publicly available at the Planetary Data System Geosciences Node: https://doi.org/10.17189/1522646. \n\nContributions: S.M. and B.C. equally led the writing of the manuscript. S.M., B.C., N.M., R.D.L., A.S., X.J., T.B. and F.M. performed data processing and interpreted the data. D.M. is the lead of SuperCam's microphone, R.C.W. the lead of the SuperCam investigation, and N.L.L. and B.C. the leads of the SuperCam Acoustics Working Group. Other investigations provided data and support to this study: J.M. is the lead of EDL's microphone; M.A., J.B., H.G. and T.T. are leading the Ingenuity project; M.H., J.H. and J.McClean are leading the MOXIE investigation; J.A.R.M., M.dlT.J. and C.E.N. are leading the MEDA investigation and mission atmospheric working group. All other co-authors provided helpful comments and inputs to the manuscript. The SuperCam team built the instrument, helps daily to operate it and to process and interpret the data. \n\nThe authors declare no competing interests. \n\nPeer review information: Nature thanks Andi Petculescu, Peter Read and Roger Waxler for their contribution to the peer review of this work.\n\nMaurice, S., Chide, B., Murdoch, N. et al. Author Correction: In situ recording of Mars soundscape. Nature (2022). https://doi.org/10.1038/s41586-022-05050-z\n\nPublished - s41586-022-04679-0.pdf
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Erratum - s41586-022-05050-z.pdf
", "abstract": "Before the Perseverance rover landing, the acoustic environment of Mars was unknown. Models predicted that: (1) atmospheric turbulence changes at centimetre scales or smaller at the point where molecular viscosity converts kinetic energy into heat, (2) the speed of sound varies at the surface with frequency and (3) high-frequency waves are strongly attenuated with distance in CO\u2082 (refs.\u20092,3,4). However, theoretical models were uncertain because of a lack of experimental data at low pressure and the difficulty to characterize turbulence or attenuation in a closed environment. Here, using Perseverance microphone recordings, we present the first characterization of the acoustic environment on Mars and pressure fluctuations in the audible range and beyond, from 20\u2009Hz to 50\u2009kHz. We find that atmospheric sounds extend measurements of pressure variations down to 1,000 times smaller scales than ever observed before, showing a dissipative regime extending over five orders of magnitude in energy. Using point sources of sound (Ingenuity rotorcraft, laser-induced sparks), we highlight two distinct values for the speed of sound that are about 10\u2009m\u2009s\u207b\u00b9 apart below and above 240\u2009Hz, a unique characteristic of low-pressure CO\u2082-dominated atmosphere. We also provide the acoustic attenuation with distance above 2\u2009kHz, allowing us to explain the large contribution of the CO\u2082 vibrational relaxation in the audible range. These results establish a ground truth for the modelling of acoustic processes, which is critical for studies in atmospheres such as those of Mars and Venus.", "date": "2022-05-26", "date_type": "published", "publication": "Nature", "volume": "605", "number": "7911", "publisher": "Nature Publishing Group", "pagerange": "653-658", "id_number": "CaltechAUTHORS:20220413-335750200", "issn": "0028-0836", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220413-335750200", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" }, { "agency": "Centre National d'\u00c9tudes Spatiales (CNES)" }, { "agency": "Ministerio de Ciencia e Innovaci\u00f3n (MICINN)", "grant_number": "PID2019-109467GB-I00" }, { "agency": "Agencia Estatal de Investigaci\u00f3n" }, { "agency": "Ministerio de Econom\u00eda, Industria y Competitividad (MINECO)", "grant_number": "10.13039/501100011033" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "corp_creators": { "items": [ "SuperCam Team" ] }, "doi": "10.1038/s41586-022-04679-0", "pmcid": "PMC9132769", "primary_object": { "basename": "41586_2022_4679_Tab1_ESM.jpg", "url": "https://authors.library.caltech.edu/records/yymhf-wyt75/files/41586_2022_4679_Tab1_ESM.jpg" }, "related_objects": [ { "basename": "41586_2022_4679_Tab2_ESM.jpg", "url": "https://authors.library.caltech.edu/records/yymhf-wyt75/files/41586_2022_4679_Tab2_ESM.jpg" }, { "basename": "s41586-022-04679-0.pdf", "url": "https://authors.library.caltech.edu/records/yymhf-wyt75/files/s41586-022-04679-0.pdf" }, { "basename": "s41586-022-05050-z.pdf", "url": "https://authors.library.caltech.edu/records/yymhf-wyt75/files/s41586-022-05050-z.pdf" }, { "basename": "41586_2022_4679_Fig5_ESM.webp", "url": "https://authors.library.caltech.edu/records/yymhf-wyt75/files/41586_2022_4679_Fig5_ESM.webp" }, { "basename": "41586_2022_4679_Fig6_ESM.webp", "url": "https://authors.library.caltech.edu/records/yymhf-wyt75/files/41586_2022_4679_Fig6_ESM.webp" }, { "basename": "41586_2022_4679_Fig7_ESM.webp", "url": "https://authors.library.caltech.edu/records/yymhf-wyt75/files/41586_2022_4679_Fig7_ESM.webp" } ], "resource_type": "article", "pub_year": "2022", "author_list": "Maurice, S.; Chide, B.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/1sty1-y4521", "eprint_id": 113329, "eprint_status": "archive", "datestamp": "2023-08-22 13:54:00", "lastmod": "2023-10-23 23:02:41", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Herd-Christopher", "name": { "family": "Herd", "given": "Christopher" }, "orcid": "0000-0001-5210-4002" }, { "id": "Bosak-Tanja", "name": { "family": "Bosak", "given": "Tanja" }, "orcid": "0000-0001-5179-5323" }, { "id": "Stack-Kathryn-M", "name": { "family": "Stack", "given": "Kathryn" }, "orcid": "0000-0003-3444-6695" }, { "id": "Sun-Vivian-Z", "name": { "family": "Sun", "given": "Vivian" }, "orcid": "0000-0003-1480-7369" }, { "id": "Gupta-Sanjeev", "name": { "family": "Gupta", "given": "Sanjeev" } }, { "id": "Shuster-David", "name": { "family": "Shuster", "given": "David" } }, { "id": "Shkolyar-Svetlana", "name": { "family": "Shkolyar", "given": "Svetlana" } }, { "id": "Weiss-Benjamin", "name": { "family": "Weiss", "given": "Benjamin" }, "orcid": "0000-0003-3113-3415" }, { "id": "Wadhwa-Meenakshi", "name": { "family": "Wadhwa", "given": "Meenakshi" }, "orcid": "0000-0001-9187-1255" }, { "id": "Hickman-Lewis-Keyron", "name": { "family": "Hickman-Lewis", "given": "Keyron" } }, { "id": "Siljestr\u00f6m-Sandra", "name": { "family": "Siljestr\u00f6m", "given": "Sandra" } }, { "id": "Mayhew-Lisa", "name": { "family": "Mayhew", "given": "Lisa" } }, { "id": "Hausrath-Elisabeth-M", "name": { "family": "Hausrath", "given": "Elisabeth" } }, { "id": "Brown-Adrian", "name": { "family": "Brown", "given": "Adrian" }, "orcid": "0000-0002-9352-6989" }, { "id": "Williford-Kenneth-H", "name": { "family": "Williford", "given": "Kenneth" }, "orcid": "0000-0003-0633-408X" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth" }, "orcid": "0000-0002-7846-7546" } ] }, "title": "The Notional Plan for Sample Collections by the Perseverance Rover for Mars Sample Return", "ispublished": "unpub", "full_text_status": "public", "note": "Submitted - essoar.10510433.1.pdf
", "abstract": "The NASA Mars 2020 Perseverance rover mission will collect a suite of scientifically compelling samples for return to Earth. On the basis of orbital data, the Mars 2020 science team identified two notional sample caches to study (1) the geology of Jezero crater, collected during the prime mission and (2) the ancient crust outside of Jezero crater, collected during a possible extended mission. \n\nJezero crater geology consists of well-preserved, Early Hesperian to Late Noachian deltaic and lacustrine deposits sourced from a river system that drained Noachian terrain. The crater floor comprises at least two distinct units of sedimentary or volcanic origin whose relationship to the deltaic deposits is presently unclear. Remotely-sensed data reveal signatures of carbonate+olivine and clay minerals within crater floor and crater margin units. Samples from within Jezero that comprise the prime mission notional sample collection thus include: crater floor units; fine- and coarse-grained delta facies, the former with potential to preserve organic matter and/or biosignatures, the latter to possibly constrain the type and timing of sediment deposition; chemical sediments with the potential to preserve biosignatures; a sample of crater rim bedrock; and at least one sample of regolith. \n\nThe region of southern Nili Planum, directly outside the western rim of Jezero crater, is geologically distinct from Jezero crater and contains diverse Early or even Pre-Noachian lithologies, that may contain records of early planetary differentiation, magnetism, paleoclimate and habitability. The notional sample collection from this region will include: layered and other basement rocks; megabreccias, which may represent blocks of (pre-)Noachian crust; basement-hosted hydrothermal fracture fill; olivine+carbonate rocks that are regionally significant and may be related to units within Jezero crater; and mafic cap unit rocks. \n\nThe samples described are notional and may change with ongoing surface investigations. However, the samples we anticipate collecting align well with community priorities for Mars exploration, addressing geologic diversity, potential ancient biologic activity on Mars, planetary evolution, volatiles, and human health hazards. \n\nMany other Mars 2020 team members were involved in this planning.", "date": "2022-02-08", "date_type": "published", "id_number": "CaltechAUTHORS:20220208-948142000", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220208-948142000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/essoar.10510433.1", "primary_object": { "basename": "essoar.10510433.1.pdf", "url": "https://authors.library.caltech.edu/records/1sty1-y4521/files/essoar.10510433.1.pdf" }, "resource_type": "conference_item", "pub_year": "2022", "author_list": "Herd, Christopher; Bosak, Tanja; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/8f6tv-a0x39", "eprint_id": 112677, "eprint_status": "archive", "datestamp": "2023-08-22 13:36:21", "lastmod": "2023-10-23 19:11:46", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Benites-Mariana", "name": { "family": "Benites", "given": "Mariana" } }, { "id": "Hein-James-R", "name": { "family": "Hein", "given": "James R." } }, { "id": "Mizell-Kira", "name": { "family": "Mizell", "given": "Kira" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Treffkorn-Jonathan", "name": { "family": "Treffkorn", "given": "Jonathan" }, "orcid": "0000-0002-4953-8245" }, { "id": "Jovane-Luigi", "name": { "family": "Jovane", "given": "Luigi" } } ] }, "title": "Geochemical insights into formation of enigmatic ironstones from Rio Grande rise, South Atlantic Ocean", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Geochemistry and Petrology; Geology; Oceanography", "note": "\u00a9 2021 Elsevier B.V.\n\nReceived 19 October 2021, Revised 15 December 2021, Accepted 21 December 2021, Available online 25 December 2021. \n\nMB acknowledges the S\u00e3o Paulo State Research Foundation (FAPESP) for PhD scholarship grant 2018/05114-8 and internship abroad scholarship grant 2019/15587-3. The FAPESP thematic project \"Marine E-tech\" is acknowledged (grant 2014/50820-7) for financing cruises RGR1 and DY094. LJ is supported by FAPESP projects 16/24946-9 and 18/17061-6. The USGS Pacific Coastal and Marine Science Center is acknowledged for hosting MB for her internship abroad. The authors thank the crew of the RV Alpha Crucis and RRS Discovery for support during sample collection. The authors thank the Brazilian Synchrotron Light Laboratory (LNLS-CNPEM) for providing beamline time, especially Dr. Douglas Galante for support with the micro-XRF analyses. \n\nAny use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. \n\nThe dataset of this research is made public through the repository DOI https://doi.org/10.6084/m9.figshare.16832056 (figshare.com/articles/dataset/Geochemistry-dataset-Ironstones/16832056). \n\nThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.", "abstract": "Rio Grande Rise (RGR) is an intraplate oceanic elevation in the South Atlantic Ocean that formed at a hotspot on the Mid-Atlantic Ridge during the Cretaceous. In spreading center and hotspot environments, ironstones form mainly by biomineralization of reduced Fe from hydrothermal fluids or oxidation of sulfide deposits. However, RGR has been considered aseismic and volcanically inactive for the past 46 Ma. Here, we investigate the origin of ironstones collected from the summit of RGR using multiple techniques: petrographic observations, X-ray diffraction, U-Th/He geochronology, and chemical composition. The ironstones from RGR consist of finely laminated goethite containing igneous rock fragments, carbonate fluorapatite, and calcite. Our results suggest that Fe oxyhydroxides were precipitated by Fe-oxidizing bacteria forming bacterial mats. The bacterial Fe mats underwent compaction, dewatering, goethite crystallization, and cementation that created the ironstone deposits. U-Th/He geochronology reveals protracted goethite minimum ages extending from the late Miocene to the Quaternary, probably due to multiple generations of mats, slow mineralization rates, and Fe-oxide dissolution-reprecipitation cycles. Flame-like goethite structures underneath FeMn crusts and a chimney-shaped goethite sample with a central channel indicate that the dewatering fluid flowed upward through the deposits, or a thermal fluid source may have been introduced from below the ironstone deposits. High Fe/Mn ratios, low trace metals contents (Ni + Co + Cu), and very low Fe/REY ratios suggest ironstone precipitation from a hydrothermal fluid; however, REY_(SN) plots and bivariate Ce_(SN) /Ce_(SN\u204e) versus Y_(SN)/Ho_(SN) and Ce_(SN) /Ce_(SN\u204e) versus Nd plots are inconclusive, and a proximal source of magma was unlikely during the period of mat formation. Given this evidence, we hypothesize that a geothermal circulation system may have facilitated ironstone mineralization at RGR.", "date": "2022-02", "date_type": "published", "publication": "Marine Geology", "volume": "444", "publisher": "Elsevier", "pagerange": "Art. No. 106716", "id_number": "CaltechAUTHORS:20220104-157882000", "issn": "0025-3227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220104-157882000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de Sao Paulo (FAPESP)", "grant_number": "2018/05114-8" }, { "agency": "Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de Sao Paulo (FAPESP)", "grant_number": "2019/15587-3" }, { "agency": "Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de Sao Paulo (FAPESP)", "grant_number": "2014/50820-7" }, { "agency": "Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de Sao Paulo (FAPESP)", "grant_number": "16/24946-9" }, { "agency": "Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de Sao Paulo (FAPESP)", "grant_number": "18/17061-6" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.margeo.2021.106716", "resource_type": "article", "pub_year": "2022", "author_list": "Benites, Mariana; Hein, James R.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/b00m3-jyd54", "eprint_id": 111276, "eprint_status": "archive", "datestamp": "2023-08-22 11:56:22", "lastmod": "2023-10-23 19:42:24", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mangold-Nicolas", "name": { "family": "Mangold", "given": "N." }, "orcid": "0000-0002-0022-0631" }, { "name": { "family": "Gupta", "given": "S." }, "orcid": "0000-0001-6415-1332" }, { "name": { "family": "Gasnault", "given": "O." }, "orcid": "0000-0002-6979-9012" }, { "name": { "family": "Dromart", "given": "G." } }, { "id": "Tarnas-Jesse-D", "name": { "family": "Tarnas", "given": "J. D." }, "orcid": "0000-0002-6256-0826" }, { "id": "Sholes-Steven-F", "name": { "family": "Sholes", "given": "S. F." }, "orcid": "0000-0003-4854-1191" }, { "name": { "family": "Horgan", "given": "B." }, "orcid": "0000-0001-6314-9724" }, { "name": { "family": "Quantin-Nataf", "given": "C." } }, { "name": { "family": "Brown", "given": "A. J." }, "orcid": "0000-0002-9352-6989" }, { "name": { "family": "Le Mou\u00e9lic", "given": "S." }, "orcid": "0000-0001-5260-1367" }, { "name": { "family": "Yingst", "given": "R. A." }, "orcid": "0000-0002-0628-4265" }, { "name": { "family": "Bell", "given": "J. F." }, "orcid": "0000-0002-2006-4074" }, { "name": { "family": "Beyssac", "given": "O." }, "orcid": "0000-0001-8879-4762" }, { "name": { "family": "Bosak", "given": "T." }, "orcid": "0000-0001-5179-5323" }, { "id": "Calef-Fred-III", "name": { "family": "Calef", "given": "F., III" }, "orcid": "0000-0002-5132-3980" }, { "id": "Ehlmann-B-L", "name": { "family": "Ehlmann", "given": "B. L." }, "orcid": "0000-0002-2745-3240" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Grotzinger-J-P", "name": { "family": "Grotzinger", "given": "J. P." }, "orcid": "0000-0001-9324-1257" }, { "name": { "family": "Hickman-Lewis", "given": "K." }, "orcid": "0000-0001-8014-233X" }, { "name": { "family": "Holm-Alwmark", "given": "S." }, "orcid": "0000-0002-0146-9324" }, { "name": { "family": "Kah", "given": "L. C." }, "orcid": "0000-0001-7172-2033" }, { "name": { "family": "Mart\u00ednez-Fr\u00edas", "given": "J." }, "orcid": "0000-0002-2609-4485" }, { "name": { "family": "McLennan", "given": "S. M." }, "orcid": "0000-0003-4259-7178" }, { "name": { "family": "Maurice", "given": "S." }, "orcid": "0000-0001-5702-8002" }, { "name": { "family": "Nu\u00f1ez", "given": "J. I." }, "orcid": "0000-0003-0930-6674" }, { "name": { "family": "Ollila", "given": "A. M." }, "orcid": "0000-0003-0479-9465" }, { "name": { "family": "Pilleri", "given": "P." }, "orcid": "0000-0003-4861-0476" }, { "name": { "family": "Rice", "given": "J. W., Jr." } }, { "name": { "family": "Rice", "given": "M." }, "orcid": "0000-0002-8370-4139" }, { "name": { "family": "Simon", "given": "J. I." }, "orcid": "0000-0002-3969-8958" }, { "name": { "family": "Shuster", "given": "D. L." }, "orcid": "0000-0003-2507-9977" }, { "id": "Stack-Kathryn-M", "name": { "family": "Stack", "given": "K. M." }, "orcid": "0000-0003-3444-6695" }, { "id": "Sun-Vivian-Z", "name": { "family": "Sun", "given": "V. Z." }, "orcid": "0000-0003-1480-7369" }, { "name": { "family": "Treiman", "given": "A. H." }, "orcid": "0000-0002-8073-2839" }, { "id": "Weiss-Benjamin-P", "name": { "family": "Weiss", "given": "B. P." }, "orcid": "0000-0003-3113-3415" }, { "name": { "family": "Wiens", "given": "R. C." }, "orcid": "0000-0002-3409-7344" }, { "name": { "family": "Williams", "given": "A. J." }, "orcid": "0000-0001-6299-0845" }, { "id": "Williams-Nathan-R", "name": { "family": "Williams", "given": "N. R." }, "orcid": "0000-0003-0602-484X" }, { "id": "Williford-Kenneth-H", "name": { "family": "Williford", "given": "K. H." }, "orcid": "0000-0003-0633-408X" } ] }, "title": "Perseverance rover reveals an ancient delta-lake system and flood deposits at Jezero crater, Mars", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2021 American Association for the Advancement of Science. \n\nReceived 12 July 2021; accepted 21 September 2021. Published online 7 October 2021. \n\nWe acknowledge the Mars 2020 project's management, engineering, and scientific teams for their diligent efforts in making this mission as effective as possible. We are grateful to Mars 2020 team members who participated in tactical and strategic science operations. We also thank the High Resolution Imaging Science Experiment (HiRISE) and CRISM instrument teams of the Mars Reconnaissance Orbiter (MRO) for the use of HiRISE images, and the Observatoire pour la Min\u00e9ralogie, l'Eau, les Glaces et l'Activit\u00e9 (OMEGA) instrument team of the Mars Express mission for the use of OMEGA data. N.M., O.G., G.D., C.Q.-N., S.L.M., P.P., and S.M. acknowledge the Centre National de Recherches Scientifiques (CNRS) and the Centre National d'Etudes Spatiales (CNES) for the research infrastructures and collaborative networks enabling their participation to rover operations. The authors appreciated helpful suggestions from reviewers.\n\nFunding: \nCentre National d'Etudes Spatiales, France (N.M., O.G., G.D., C.Q.-N., S.L.M., P.P., S.M.); NASA Mars 2020 Project (J.D.T., S.F.S., B.H., J.F.B., K.A.F., K.H.W., K.M.S., R.C.W., B.L.E., S.M.M., R.A.Y., J.I.N.); NASA Planetary Science Division, Mars Program (J.I.S.); NASA M2020 Participating Scientist Program under Grant #80NSSC21K0332 (A.J.W.); NASA Mars 2020 Returned Sample Science Participating Scientist Program (RSSPS) award numbers 80NSSC20K0234 (T.B.) and 80NSSC20K0238 (B.P.W.); NASA Post-Doctoral program (JDT); UK Space Agency Aurora program (S.G.); UK Space Agency Aurora Research Fellowship (K.H.-L.); International Postdoc grant from the Swedish Research Council (grant no. 2017-06388) (S.H.-A.); Simons Foundation Collaboration on the Origins of Life, grant #327126 (T.B.).\n\nAuthor contributions: \nConceptualization: N.M., S.G., and G.D. Methodology \u2013 data processing: O.G., P.P., S.L.M., J.F.B., J.I.N., M.R., A.M.O., B.H., C.Q.-N., J.D.T., R.A.Y., and L.C.K. Project administration: J.F.B., K.A.F., K.H.W., K.M.S., R.C.W., and S.M. Writing \u2013 original draft: N.M., S.G., G.D., A.J.B., B.H., B.W., J.F.B., O.G., and D.L.S. Writing \u2013 review & editing: N.M., S.G., O.G., G.D., J.D.T., S.F.S., B.H., R.A.Y., J.F.B., O.B., T.B., B.E., K.A.F., J.P.G., K.H.-L., S.H.-A., L.C.K., J.M.-F., S.M.L., J.I.N., J.W.R., M.R., J.I.S., D.L.S., K.M.S., V.Z.S., A.H.T., B.P.W., R.C.W., A.J.W., and K.H.W. Visualization: N.M., G.D., S.L.M., C.Q.-N., B.H., J.D.T., M.R., J.F.B., S.F.S., F.C., and N.R.W.\n\nThe authors declare no competing interests.\n\nData and materials availability: \nThe data used in this paper are available on the Planetary Data System (PDS). Tables S1 and S2 give links to PDS web pages for the Perseverance rover SuperCam and Mastcam-Z instruments and list the image numbers used in Figs. 1 to 4 and figs. S2 to S4, S6, S7, and S12. Data from the OMEGA instrument on Mars Express, used in fig. S11, are available at https://pds-geosciences.wustl.edu/mex/mex-m-omega-2-edr-flight-v1/mexomg-0001/data/ in the \"gem04\" and \"gem22\" directories. Data from the HiRISE instrument on MRO, used in Fig. 1 and figs. S1 and S9 to S11, are available at https://hirise-pds.lpl.arizona.edu/PDS/EDR/ESP/ORB_036600_036699/ESP_036618_1985/, https://hirise-pds.lpl.arizona.edu/PDS/EDR/ESP/ORB_037100_037199/ESP_037119_1985/, https://hirise-pds.lpl.arizona.edu/PDS/EDR/PSP/ORB_002300_002399/PSP_002387_1985/, and https://hirise-pds.lpl.arizona.edu/PDS/EDR/PSP/ORB_003700_003799/PSP_003798_1985/. The CRISM data used for fig. S11 are available at https://pds-geosciences.wustl.edu/mro/mro-m-crism-3-rdr-targeted-v1/mrocr_2101/trdr/2007/2007_029/hrl000040ff/hrl000040ff_07_if183l_trr3.img. The Context Camera image mosaic of Jezero used in Fig. 5 and fig. S1 is available at the United States Geological Survey https://astrogeology.usgs.gov/search/map/Mars/Mars2020/JEZ_ctx_B_soc_008_orthoMosaic_6m_Eqc_latTs0_lon0. The Entry, Descent, Landing (EDL) image used in fig. S5 is available at https://mars.nasa.gov/mars2020/multimedia/raw-images/. Our cobble size measurements, used to produce Fig. 3E and fig. S7, are provided in data S1.\n\nSupplemental Material - science.abl4051_data_s1.zip
Supplemental Material - science.abl4051_sm.pdf
", "abstract": "Observations from orbital spacecraft have shown that Jezero crater on Mars contains a prominent fan-shaped body of sedimentary rock deposited at its western margin. The Perseverance rover landed in Jezero crater in February 2021. We analyze images taken by the rover in the 3 months after landing. The fan has outcrop faces, which were invisible from orbit, that record the hydrological evolution of Jezero crater. We interpret the presence of inclined strata in these outcrops as evidence of deltas that advanced into a lake. In contrast, the uppermost fan strata are composed of boulder conglomerates, which imply deposition by episodic high-energy floods. This sedimentary succession indicates a transition from sustained hydrologic activity in a persistent lake environment to highly energetic short-duration fluvial flows.", "date": "2021-11-05", "date_type": "published", "publication": "Science", "volume": "374", "number": "6568", "publisher": "American Association for the Advancement of Science", "pagerange": "711-717", "id_number": "CaltechAUTHORS:20211008-143531053", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211008-143531053", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Centre National d'\u00c9tudes Spatiales (CNES)" }, { "agency": "NASA", "grant_number": "80NSSC21K0332" }, { "agency": "NASA", "grant_number": "80NSSC20K0234" }, { "agency": "NASA", "grant_number": "80NSSC20K0238" }, { "agency": "NASA Postdoctoral Program" }, { "agency": "United Kingdom Space Agency (UKSA)" }, { "agency": "Swedish Research Council", "grant_number": "2017-06388" }, { "agency": "Simons Foundation", "grant_number": "327126" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.abl4051", "primary_object": { "basename": "science.abl4051_data_s1.zip", "url": "https://authors.library.caltech.edu/records/b00m3-jyd54/files/science.abl4051_data_s1.zip" }, "related_objects": [ { "basename": "science.abl4051_sm.pdf", "url": "https://authors.library.caltech.edu/records/b00m3-jyd54/files/science.abl4051_sm.pdf" } ], "resource_type": "article", "pub_year": "2021", "author_list": "Mangold, N.; Gupta, S.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/m52av-8p182", "eprint_id": 112012, "eprint_status": "archive", "datestamp": "2023-08-22 11:48:51", "lastmod": "2023-10-23 20:51:35", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Taylor-Susan", "name": { "family": "Taylor", "given": "Susan" }, "orcid": "0000-0002-5443-9487" }, { "id": "Treffkorn-Jonathan", "name": { "family": "Treffkorn", "given": "Jonathan" }, "orcid": "0000-0002-4953-8245" }, { "id": "Lever-James-H", "name": { "family": "Lever", "given": "James H." } }, { "id": "Gow-Anthony-L", "name": { "family": "Gow", "given": "Anthony L." } } ] }, "title": "\u00b3He flux obtained from South Pole air and snow-ice and its connection to interplanetary dust particles", "ispublished": "pub", "full_text_status": "public", "keywords": "Space and Planetary Science; Geophysics", "note": "\u00a9 2021 The Meteoritical Society. This article has been contributed to by US Government employees and their work is in the public domain in the USA. \n\nIssue Online: 18 November 2021; Version of Record online: 15 November 2021; Manuscript accepted: 02 October 2021; Manuscript received: 27 May 2021. \n\nCollection of the South Pole air filters was funded by NASA's Emerging Worlds program 15-EW15-2-009, with added support from NSF's Antarctic Program. We thank NASA and NSF for their support. As authors, we assert no affiliation or involvement in an organization or entity with a financial or nonfinancial interest in the subject matter or materials discussed in this manuscript. We thank Dr. Hope Ishii and an unknown reviewer for their helpful comments and suggestions. \n\nData Availability Statement: Data available in article supplementary material.\n\nPublished - maps.13759.pdf
Supplemental Material - maps13759-sup-0001-appendixa.pdf
Supplemental Material - maps13759-sup-0002-appendixb.pdf
Supplemental Material - maps13759-sup-0003-appendixc.docx
Supplemental Material - maps13759-sup-0004-appendixd.docx
", "abstract": "Researchers have characterized extraterrestrial (ET) helium, likely carried by interplanetary dust particles (IDPs), in deep-sea sediments spanning more than the last 100\u2009Myr. Here we complement those low resolution and deep time studies by measuring He in modern Antarctic air and recent ice. We analyzed 180 air filter samples collected in 2017 and 2018 at the South Pole and detected \u00b3He above blank levels in 178. The filters collected during the austral springs had elevated \u00b3He in multiple subsamples indicating the presence of many individual IDPs and potentially, a temporal variation in the ET small particle flux. Our calculated mean \u00b3He flux of 1.4\u2009\u00b1\u20091.2\u2009\u00d7\u200910\u207b\u00b9\u00b2\u2009cc\u2009STP\u2009cm\u207b\u00b2 ka\u207b\u00b9 is the first such measurement from air samples. We also melted, filtered, and analyzed one hundred and forty-one 1\u2009m-long ice sections from a \u02dc2000-yr-old South Pole core. We detected \u00b3He above blank levels in 139 of the 141 ice core samples and calculated an average flux of 1.2\u2009\u00b1\u20090.3\u2009\u00d7\u200910\u207b\u00b9\u00b2\u2009cc\u2009STP\u2009cm\u207b\u00b2\u2009ka\u207b\u00b9. Our two flux values are within a factor of two of those calculated from stratospheric IDP concentrations, those previously measured for sections of the GISP2 and Vostok ice cores, and from sediment cores from different locations and ages. The similarity of these flux values over disparate time scales (1\u201310\u2078\u2009yr) and geographic locations (90\u00b0 S to equator) indicates modest temporal variability and remarkable agreement among diverse IDP archives. These data provide a compelling link from IDPs collected in the stratosphere to those recorded in deep time sedimentary archives.", "date": "2021-11", "date_type": "published", "publication": "Meteoritics and Planetary Science", "volume": "56", "number": "11", "publisher": "Meteoritical Society", "pagerange": "1988-2001", "id_number": "CaltechAUTHORS:20211123-195853267", "issn": "1086-9379", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211123-195853267", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "15-EW15-2-009" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/maps.13759", "primary_object": { "basename": "maps13759-sup-0004-appendixd.docx", "url": "https://authors.library.caltech.edu/records/m52av-8p182/files/maps13759-sup-0004-appendixd.docx" }, "related_objects": [ { "basename": "maps.13759.pdf", "url": "https://authors.library.caltech.edu/records/m52av-8p182/files/maps.13759.pdf" }, { "basename": "maps13759-sup-0001-appendixa.pdf", "url": "https://authors.library.caltech.edu/records/m52av-8p182/files/maps13759-sup-0001-appendixa.pdf" }, { "basename": "maps13759-sup-0002-appendixb.pdf", "url": "https://authors.library.caltech.edu/records/m52av-8p182/files/maps13759-sup-0002-appendixb.pdf" }, { "basename": "maps13759-sup-0003-appendixc.docx", "url": "https://authors.library.caltech.edu/records/m52av-8p182/files/maps13759-sup-0003-appendixc.docx" } ], "resource_type": "article", "pub_year": "2021", "author_list": "Farley, Kenneth A.; Taylor, Susan; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/s6be7-ykm82", "eprint_id": 110175, "eprint_status": "archive", "datestamp": "2023-08-22 10:43:12", "lastmod": "2023-10-23 18:19:57", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shaw-Joseph-M", "name": { "family": "Shaw", "given": "J. M." }, "orcid": "0000-0001-9231-2834" }, { "id": "Evenstar-Laura", "name": { "family": "Evenstar", "given": "L." }, "orcid": "0000-0002-2412-357X" }, { "id": "Cooper-F-J", "name": { "family": "Cooper", "given": "F. J." } }, { "id": "Adams-B-A", "name": { "family": "Adams", "given": "B. A." } }, { "id": "Boyce-Adrian-J", "name": { "family": "Boyce", "given": "A. J." }, "orcid": "0000-0002-9680-0787" }, { "id": "Hofmann-Florian", "name": { "family": "Hofmann", "given": "F." }, "orcid": "0000-0002-9836-2338" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "A Rusty Record of Weathering and Groundwater Movement in the Hyperarid Central Andes", "ispublished": "pub", "full_text_status": "public", "keywords": "hematite (U-Th-Sm)/He geochronology; porphyry copper deposits; supergene processes; weathering; oxygen isotope analysis; Atacama Desert", "note": "\u00a9 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. \n\nIssue Online: 03 August 2021; Version of Record online: 03 August 2021; Accepted manuscript online: 20 July 2021; Manuscript accepted: 14 July 2021; Manuscript revised: 07 July 2021; Manuscript received: 09 March 2021. \n\nThis work was funded by a NERC GW4+ UK DTP Studentship (NE/L002434/1) with CASE support from BHP. Additional funding for the (U-Th-Sm)/He work was provided by a Student Research Grant from SEG (SRG18-104; J. Shaw) and a Royal Society Grant (RG140683; F. Cooper). Isotopic analyses were supported by a NERC Isotope Geosciences Facilities Grant (IP-1752-1117; F. Cooper). The authors are grateful to BHP for permitting mine visits, Ed Bunker for sample collection, and Guillerme Santos, Reinaldo Guzman, and Lia Ituarte for advice and logistical assistance. The authors thank Martin Smith for feedback on a draft manuscript and Mark Cuthbert for discussion on water tables. The authors thank Pete Reiners and Carlos Marquardt for their constructive reviews, and Peter van der Beek for his editorial handling. \n\nData Availability Statement: Data reported in this paper can be accessed at the BGS NGDC repository. Data reported in Cooper et al. (2016) can be accessed at the GSA repository: https://gsapubs.figshare.com/articles/journal_contribution/Supplemental_material_Aridity-induced_Miocene_canyon_incision_in_the_Central_Andes/12533894\n\nPublished - 2021GC009759.pdf
Supplemental Material - 2021gc009759-sup-0001-supporting_information_si-s01.docx
", "abstract": "The Atacama Desert, on the western margin of the Central Andes, hosts some of the world's largest porphyry copper deposits (PCDs). Despite a hyperarid climate, many of these PCDs have undergone secondary \"supergene\" enrichment, whereby copper has been concentrated via groundwater-driven leaching and reprecipitation, yielding supergene profiles containing valuable records of weathering and landscape evolution. We combine hematite (U-Th-Sm)/He geochronology and oxygen isotope analysis to compare the weathering histories of two Andean PCDs and test the relative importance of climate and tectonics in controlling both enrichment and water table movement. At Cerro Colorado, in the Precordillera, hematite precipitation records prolonged weathering from \u223c31 to \u223c2 Ma, tracking water table descent following aridity-induced canyon incision from the late Miocene onward. By contrast, hematite at Spence, within the Central Depression, is mostly younger than \u223c10.5 Ma, suggesting exhumation ended much later. A heavy oxygen isotopic signature for Spence hematite suggests that upwelling formation water has been an important source of groundwater, accounting for a high modern water table despite persistent hyperaridity, whereas isotopically light hematite at Cerro Colorado formed in the presence of meteoric water. Compared with published paleo-environmental and sedimentological records, our data show that weathering can persist beneath appreciable post-exhumation cover, under hyperarid conditions unconducive to enrichment. The susceptibility of each deposit to aridity-induced water table descent, canyon incision and deep weathering has been controlled by recharge characteristics and morphotectonic setting. Erosional exhumation, rather than aridity-induced water table decay, appears to be more important for the development of supergene enrichment.", "date": "2021-08", "date_type": "published", "publication": "Geochemistry, Geophysics, Geosystems", "volume": "22", "number": "8", "publisher": "American Geophysical Union", "pagerange": "Art. No. e2021GC009759", "id_number": "CaltechAUTHORS:20210809-194137903", "issn": "1525-2027", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210809-194137903", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Natural Environment Research Council (NERC)", "grant_number": "NE/L002434/1" }, { "agency": "Society of Economic Geologists Foundation", "grant_number": "SRG18-104" }, { "agency": "Royal Society", "grant_number": "RG140683" }, { "agency": "Natural Environment Research Council (NERC)", "grant_number": "IP-1752-1117" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2021gc009759", "primary_object": { "basename": "2021GC009759.pdf", "url": "https://authors.library.caltech.edu/records/s6be7-ykm82/files/2021GC009759.pdf" }, "related_objects": [ { "basename": "2021gc009759-sup-0001-supporting_information_si-s01.docx", "url": "https://authors.library.caltech.edu/records/s6be7-ykm82/files/2021gc009759-sup-0001-supporting_information_si-s01.docx" } ], "resource_type": "article", "pub_year": "2021", "author_list": "Shaw, J. M.; Evenstar, L.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ca406-pjy96", "eprint_id": 110251, "eprint_status": "archive", "datestamp": "2023-08-22 10:43:53", "lastmod": "2023-10-23 17:16:09", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Cohen-Barbara-A", "name": { "family": "Cohen", "given": "Barbara A." }, "orcid": "0000-0001-5896-5903" }, { "name": { "family": "Young", "given": "Kelsey E." } }, { "name": { "family": "Zellner", "given": "Nicolle E. B." } }, { "name": { "family": "Zacny", "given": "Kris" } }, { "name": { "family": "Yingst", "given": "R. Aileen" }, "orcid": "0000-0002-0628-4265" }, { "name": { "family": "Watkins", "given": "Ryan N." } }, { "name": { "family": "Warwick", "given": "Richard" } }, { "name": { "family": "Valencia", "given": "Sarah N." } }, { "name": { "family": "Swindle", "given": "Timothy D." } }, { "name": { "family": "Robbins", "given": "Stuart J." }, "orcid": "0000-0002-8585-2549" }, { "name": { "family": "Petro", "given": "Noah E." } }, { "name": { "family": "Nicoletti", "given": "Anthony" } }, { "name": { "family": "Moriarty", "given": "Dan P." } }, { "name": { "family": "Lynch", "given": "Richard" } }, { "name": { "family": "Indyk", "given": "Stephen J." } }, { "name": { "family": "Gross", "given": "Juliane" } }, { "name": { "family": "Grier", "given": "Jennifer A." } }, { "name": { "family": "Grant", "given": "John A." }, "orcid": "0000-0001-8276-1281" }, { "name": { "family": "Ginyard", "given": "Amani" } }, { "name": { "family": "Fassett", "given": "Caleb I." }, "orcid": "0000-0001-9155-3804" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "name": { "family": "Farcy", "given": "Benjamin J." }, "orcid": "0000-0001-5159-6551" }, { "id": "Ehlmann-B-L", "name": { "family": "Ehlmann", "given": "Bethany L." }, "orcid": "0000-0002-2745-3240" }, { "name": { "family": "Dyar", "given": "M. Darby" }, "orcid": "0000-0003-4272-793X" }, { "name": { "family": "Daelemans", "given": "Gerard" } }, { "name": { "family": "Curran", "given": "Natalie M." } }, { "name": { "family": "van der Bogert", "given": "Carolyn H." }, "orcid": "0000-0003-2882-7037" }, { "name": { "family": "Arevalo", "given": "Ricardo D." } }, { "name": { "family": "Anderson", "given": "F. Scott" } } ] }, "title": "In Situ Geochronology for the Next Decade: Mission Designs for the Moon, Mars, and Vesta", "ispublished": "pub", "full_text_status": "public", "keywords": "Earth-moon system; Selenology; Mars; Main belt asteroids; Lunar geochronology; Cosmochronology", "note": "\u00a9 2021. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. \n\nReceived 2020 October 14; revised 2021 January 26; accepted 2021 March 8; published 2021 August 3. \n\nLunar Mission Concepts and High-priority Landing Sites. \n\nThis work was supported by the Planetary Mission Concept Studies program. Additional analysis was supported by NASA's Solar System Exploration Research Virtual Institute Center for Lunar and Asteroid Surface Science (CLASS). This research has made use of NASA's Astrophysics Data System.\n\nPublished - Cohen_2021_Planet._Sci._J._2_145.pdf
Submitted - 2101.01131.pdf
", "abstract": "Geochronology is an indispensable tool for reconstructing the geologic history of planets, essential to understanding the formation and evolution of our solar system. Bombardment chronology bounds models of solar system dynamics, as well as the timing of volatile, organic, and siderophile element delivery. Absolute ages of magmatic products provide constraints on the dynamics of magma oceans and crustal formation, as well as the longevity and evolution of interior heat engines and distinct mantle/crustal source regions. Absolute dating also relates habitability markers to the timescale of evolution of life on Earth. However, the number of terrains important to date on worlds of the inner solar system far exceeds our ability to conduct sample return from all of them. In preparation for the upcoming Decadal Survey, our team formulated a set of medium-class (New Frontiers) mission concepts to three different locations (the Moon, Mars, and Vesta) where sites that record solar system bombardment, magmatism, and habitability are uniquely preserved and accessible. We developed a notional payload to directly date planetary surfaces, consisting of two instruments capable of measuring radiometric ages, an imaging spectrometer, optical cameras to provide site geologic context and sample characterization, a trace-element analyzer to augment sample contextualization, and a sample acquisition and handling system. Landers carrying this payload to the Moon, Mars, and Vesta would likely fit into the New Frontiers cost cap in our study (~$1B). A mission of this type would provide crucial constraints on planetary history while also enabling a broad suite of complementary investigations.", "date": "2021-08", "date_type": "published", "publication": "Planetary Science Journal", "volume": "2", "number": "4", "publisher": "American Astronomical Society", "pagerange": "Art. No.145", "id_number": "CaltechAUTHORS:20210813-181202655", "issn": "2632-3338", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210813-181202655", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.3847/PSJ/abedbf", "primary_object": { "basename": "2101.01131.pdf", "url": "https://authors.library.caltech.edu/records/ca406-pjy96/files/2101.01131.pdf" }, "related_objects": [ { "basename": "Cohen_2021_Planet._Sci._J._2_145.pdf", "url": "https://authors.library.caltech.edu/records/ca406-pjy96/files/Cohen_2021_Planet._Sci._J._2_145.pdf" } ], "resource_type": "article", "pub_year": "2021", "author_list": "Cohen, Barbara A.; Young, Kelsey E.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/r71gg-vvk61", "eprint_id": 112286, "eprint_status": "archive", "datestamp": "2023-08-22 10:34:04", "lastmod": "2023-10-23 17:38:39", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hofmann-Florian", "name": { "family": "Hofmann", "given": "Florian" }, "orcid": "0000-0002-9836-2338" }, { "id": "Cooperdock-Emily-H-G", "name": { "family": "Cooperdock", "given": "Emily H. G." }, "orcid": "0000-0002-0154-8719" }, { "id": "West-A-Joshua", "name": { "family": "West", "given": "A. Joshua" }, "orcid": "0000-0001-6909-1471" }, { "id": "Hildebrandt-Dominic", "name": { "family": "Hildebrandt", "given": "Dominic" }, "orcid": "0000-0002-9891-0664" }, { "id": "Str\u00f6\u00dfner-Kathrin", "name": { "family": "Str\u00f6\u00dfner", "given": "Kathrin" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Exposure dating of detrital magnetite using \u00b3He enabled by microCT and calibration of the cosmogenic \u00b3He production rate in magnetite", "ispublished": "pub", "full_text_status": "public", "keywords": "General Earth and Planetary Sciences; General Environmental Science", "note": "\u00a9 Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. \n\nReceived: 22 Mar 2021 \u2013 Discussion started: 01 Apr 2021 \u2013 Accepted: 16 Jun 2021 \u2013 Published: 15 Jul 2021. \n\nWe thank Tautis Skorka at the Molecular Imaging Center at the University of Southern California for microCT scanning and Jonathan Treffkorn for helium mass spectrometry at Caltech. Reviews by Samuel Niedermann and Pierre-Henri Blard as well as editorial handling by Hella Wittmann-Oelze and Greg Balco helped to improve the paper. \n\nFunding was provided by Southern California Earthquake Center 2020 award no. 20146 to Kenneth A. Farley, Emily H. G. Cooperdock, A. Joshua West, and Florian Hofmann. Student contributions at Ludwig-Maximilians-Universit\u00e4t M\u00fcnchen were funded by Studi_forscht@GEO grant S20-F17 awarded to Florian Hofmann. \n\nThis research has been supported by the Southern California Earthquake Center (grant no. 20146) and the Ludwig-Maximilians-Universit\u00e4t M\u00fcnchen (Studi_forscht@GEO, grant no. S20-F17). \n\nAuthor contributions. FH, EHGC, AJW, and KAF conceptualized the study and acquired funding. FH, DH, and KS carried out mineral separation, sample processing, and data analysis. FH, EHGC, AJW, and KAF contributed to the interpretation of the data. The paper and figures were prepared by FH and edited and reviewed by all co-authors. \n\nThe authors declare that they have no conflict of interest. \n\nReview statement. This paper was edited by Hella Wittmann-Oelze and reviewed by Samuel Niedermann and Pierre-Henri Blard.\n\nPublished - gchron-3-395-2021.pdf
", "abstract": "We test whether X-ray micro-computed tomography (microCT) imaging can be used as a tool for screening magnetite grains to improve the accuracy and precision of cosmogenic \u00b3He exposure dating. We extracted detrital magnetite from a soil developed on a fanglomerate at Whitewater, California, which was offset by the Banning strand of the San Andreas Fault. This study shows that microCT screening can distinguish between inclusion-free magnetite and magnetite with fluid or common solid inclusions. Such inclusions can produce bulk 3He concentrations that are significantly in excess of the expected spallation production. We present Li concentrations, major and trace element analyses, and estimated magnetite (U\u2013Th)\u2009/\u2009He cooling ages of samples in order to model the contribution from fissiogenic, nucleogenic, and cosmogenic thermal neutron production of \u00b3He. We show that mineral inclusions in magnetite can produce \u00b3He concentrations of up to 4 times that of the spallation component, leading to erroneous exposure ages. Therefore, grains with inclusions must be avoided in order to facilitate accurate and precise magnetite \u00b3He exposure dating. Around 30\u2009% of all grains were found to be without inclusions, as detectable by microCT, with the largest proportion of suitable grains in the grain size range of 400\u2013800\u2009\u00b5m. While grains with inclusions have \u00b3He concentrations far in excess of the values expected from existing \u00b9\u2070Be and \u00b2\u2076Al data in quartz at the Whitewater site, magnetite grains without inclusions have concentrations close to the predicted depth profile. We measured \u00b3He concentrations in aliquots without inclusions and corrected them for Li-produced components. By comparing these data to the known exposure age of 53.5\u2009\u00b1\u20092.2\u2009ka, we calibrate a production rate for magnetite 3He at sea level and high latitude (SLHL) of 116\u2009\u00b1\u200913\u2009at\u2009g\u207b\u00b9\u2009a\u207b\u00b9. We suggest that this microCT screening approach can be used to improve the quality of cosmogenic \u00b3He measurements of magnetite and other opaque mineral phases for exposure age and detrital studies.", "date": "2021-07-15", "date_type": "published", "publication": "Geochronology", "volume": "3", "number": "2", "publisher": "European Geosciences Union", "pagerange": "395-414", "id_number": "CaltechAUTHORS:20211208-560311000", "issn": "2628-3719", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211208-560311000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "20146" }, { "agency": "Ludwig-Maximilians-Universit\u00e4t M\u00fcnchen", "grant_number": "Studi_forscht@GEO, S20-F17" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.5194/gchron-3-395-2021", "primary_object": { "basename": "gchron-3-395-2021.pdf", "url": "https://authors.library.caltech.edu/records/r71gg-vvk61/files/gchron-3-395-2021.pdf" }, "resource_type": "article", "pub_year": "2021", "author_list": "Hofmann, Florian; Cooperdock, Emily H. G.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/08dr4-w6943", "eprint_id": 109668, "eprint_status": "archive", "datestamp": "2023-08-22 10:22:51", "lastmod": "2023-10-23 16:59:13", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Scheller-Eva-L", "name": { "family": "Scheller", "given": "Eva L." }, "orcid": "0000-0002-9981-5802" }, { "id": "Swindle-Carl", "name": { "family": "Swindle", "given": "Carl" }, "orcid": "0000-0002-8706-9398" }, { "id": "Grotzinger-J-P", "name": { "family": "Grotzinger", "given": "John" }, "orcid": "0000-0001-9324-1257" }, { "id": "Barnhart-Holly", "name": { "family": "Barnhart", "given": "Holly" }, "orcid": "0000-0002-0842-9464" }, { "id": "Bhattacharjee-Surjyendu", "name": { "family": "Bhattacharjee", "given": "Surjyendu" }, "orcid": "0000-0002-3924-0357" }, { "id": "Ehlmann-B-L", "name": { "family": "Ehlmann", "given": "Bethany L." }, "orcid": "0000-0002-2745-3240" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Ken" }, "orcid": "0000-0002-7846-7546" }, { "id": "Fischer-W-W", "name": { "family": "Fischer", "given": "Woodward W." }, "orcid": "0000-0002-8836-3054" }, { "id": "Greenberger-Rebecca-N", "name": { "family": "Greenberger", "given": "Rebecca" }, "orcid": "0000-0003-1583-0261" }, { "id": "Ingalls-Miquela", "name": { "family": "Ingalls", "given": "Miquela" }, "orcid": "0000-0002-7451-2944" }, { "id": "Martin-Peter-E", "name": { "family": "Martin", "given": "Peter E." }, "orcid": "0000-0003-4243-2090" }, { "id": "Osorio\u2010Rodriguez-Daniela", "name": { "family": "Osorio\u2010Rodriguez", "given": "Daniela" }, "orcid": "0000-0001-6676-4124" }, { "id": "Smith-Ben-P", "name": { "family": "Smith", "given": "Ben P." }, "orcid": "0000-0003-3189-8717" } ] }, "title": "Formation of Magnesium Carbonates on Earth and Implications for Mars", "ispublished": "pub", "full_text_status": "public", "keywords": "carbonate; magnesite; Mars; Mars2020; Perseverance; review", "note": "\u00a9 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. \n\nIssue Online: 12 July 2021; Version of Record online: 12 July 2021; Accepted manuscript online: 22 June 2021; Manuscript accepted: 29 May 2021; Manuscript revised: 28 May 2021; Manuscript received: 25 January 2021. \n\nThis project was supported by the Simons Foundation grant \"Planetary Context of Habitability and Exobiology,\" and the Simons Foundation Collaboration on the Origins of Life. E. L. Scheller was supported by NESSF grant #80NSSC18K1255. C. Swindle was supported by NSF Graduate Research Fellowship under grant #DGE-1745301. The authors thank Ken Williford, Emily Cardarelli, Paulo Vasconcelos, Cecilia Sanders, Ted Present, Dustin Morris, Peter Kelemen, and Bradley Garczynski for invaluable discussions. They thank all authors and editors for their permission to reuse images for figures. They extend special thanks and acknowledgments to Pablo Garc\u00eda del Real for kindly providing unpublished, original pictures for this study and for invaluable discussion. Last, they thank Tanja Bosak, Frieder Klein, and an anonymous reviewer for their insightful reviews and suggestions that led to the improvement of the study. \n\nThe authors declare no conflicts of interest relevant to this study. \n\nData Availability Statement: All recognition of reused images should be given to original authors with references that are denoted on each figure. Spectral data from Figure 1 can be found in Mandon et al. (2020) and Ehlmann et al. (2009). Isotopic data from Figure 6 is a compilation of data color coded according to references as given in the figure legend. A table of data has been uploaded to the Caltech Data Repository: 10.22002/D1.1971.\n\nPublished - 2021JE006828.pdf
", "abstract": "Magnesium carbonates have been identified within the landing site of the Perseverance rover mission. This study reviews terrestrial analog environments and textural, mineral assemblage, isotopic, and elemental analyses that have been applied to establish formation conditions of magnesium carbonates. Magnesium carbonates form in five distinct settings: ultramafic rock-hosted veins, the matrix of carbonated peridotite, nodules in soil, alkaline lake, and playa deposits, and as diagenetic replacements within lime\u2014and dolostones. Dominant textures include fine-grained or microcrystalline veins, nodules, and crusts. Microbial influences on formation are recorded in thrombolites, stromatolites, crinkly, and pustular laminites, spheroids, and filamentous microstructures. Mineral assemblages, fluid inclusions, and carbon, oxygen, magnesium, and clumped isotopes of carbon and oxygen have been used to determine the sources of carbon, magnesium, and fluid for magnesium carbonates as well as their temperatures of formation. Isotopic signatures in ultramafic rock-hosted magnesium carbonates reveal that they form by either low-temperature meteoric water infiltration and alteration, hydrothermal alteration, or metamorphic processes. Isotopic compositions of lacustrine magnesium carbonate record precipitation from lake water, evaporation processes, and ambient formation temperatures. Assessment of these features with similar analytical techniques applied to returned Martian samples can establish whether carbonates on ancient Mars were formed at high or low temperature conditions in the surface or subsurface through abiotic or biotic processes. The timing of carbonate formation processes could be constrained by \u00b9\u2074\u2077Sm-\u00b9\u2074\u00b3Nd isochron, U-Pb concordia, \u00b2\u2070\u2077Pb-\u00b2\u2070\u2076Pb isochron radiometric dating as well as \u00b3He, \u00b2\u00b9Ne, \u00b2\u00b2Ne, or \u00b3\u2076Ar surface exposure dating of returned Martian magnesium carbonate samples.", "date": "2021-07", "date_type": "published", "publication": "Journal of Geophysical Research. Planets", "volume": "126", "number": "7", "publisher": "American Geophysical Union", "pagerange": "Art. No. e2021JE006828", "id_number": "CaltechAUTHORS:20210630-151049458", "issn": "2169-9097", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210630-151049458", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Simons Foundation" }, { "agency": "NASA Earth and Space Science Fellowship", "grant_number": "80NSSC18K1255" }, { "agency": "NSF Graduate Research Fellowship", "grant_number": "DGE\u20101745301" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2021je006828", "primary_object": { "basename": "2021JE006828.pdf", "url": "https://authors.library.caltech.edu/records/08dr4-w6943/files/2021JE006828.pdf" }, "resource_type": "article", "pub_year": "2021", "author_list": "Scheller, Eva L.; Swindle, Carl; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/7rvb6-ytq31", "eprint_id": 109151, "eprint_status": "archive", "datestamp": "2023-08-22 09:53:09", "lastmod": "2023-10-23 17:41:53", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Larsen-I-J", "name": { "family": "Larsen", "given": "I. J." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Lamb-M-P", "name": { "family": "Lamb", "given": "M. P." }, "orcid": "0000-0002-5701-0504" }, { "id": "Pritchard-C-J", "name": { "family": "Pritchard", "given": "C. J." } } ] }, "title": "Empirical evidence for cosmogenic \u00b3He production by muons", "ispublished": "pub", "full_text_status": "public", "keywords": "3He; cosmogenic nuclides; muon; exposure dating; Columbia River Basalt; mantle helium", "note": "\u00a9 2021 Elsevier B.V. \n\nReceived 30 June 2020, Revised 8 February 2021, Accepted 11 February 2021, Available online 19 February 2021. \n\nWe thank Karin Lehnigk, Scott David, and Madison Douglas for assistance in the field, Devon Dunajski, Patrick Scordato, and Alice Hough for helping separate minerals, Johnathan Treffkorn for assistance with \u00b3He measurements, and Stephen Riedel and Graysen Bjork for helpful information pertaining to the Cheney core. We thank Marissa Tremblay for a constructive review. This research was supported by a collaborative NSF award (1529528, 1529110) to I.J.L., K.A.F. and M.P.L. \n\nCRediT authorship contribution statement:\nI.J. Larsen: Conceptualization, Investigation, Writing \u2013 original draft. K.A. Farley: Conceptualization, Investigation, Writing \u2013 review & editing. M.P. Lamb: Conceptualization, Investigation, Software, Writing \u2013 review & editing. C.J. Pritchard: Resources, Writing \u2013 review & editing. \n\nThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\n\nSupplemental Material - 1-s2.0-S0012821X21000844-mmc1.xlsx
Supplemental Material - 1-s2.0-S0012821X21000844-mmc2.xlsx
Supplemental Material - 1-s2.0-S0012821X21000844-mmc3.xlsx
", "abstract": "Cosmic ray muons penetrate deeply into rock where they interact with atoms to produce cosmogenic nuclides. Incorporation of the muon contribution to the production rates of cosmogenic nuclides increases the accuracy of exposure dates, burial ages, and erosion rates inferred from measured nuclide concentrations. In the absence of empirical evidence, it is generally assumed that muons do not produce \u00b3He, a cosmogenic nuclide commonly used for exposure dating. Here we assess whether muons produce \u00b3He by measuring He isotope concentrations in pyroxene and ilmenite from a \u223c300 m deep drill core and other subsurface samples of the mid-Miocene Columbia River Basalt in Washington, USA. \u00b3He concentrations in our samples exhibit an exponential decline with depth with an e-folding length of 32.4 m, which corresponds to an attenuation length for \u00b3He production of 8780 g cm\u207b\u00b2. The deeply penetrating exponential is diagnostic of \u00b3He production by cosmic ray muons. Assuming no erosion, we constrain the minimum surface muonogenic production rate to be 0.23 atom g\u207b\u00b9 pyroxene yr\u207b\u00b9, whereas when incorporating erosion the production rate is 0.45 atom g\u207b\u00b9 pyroxene yr\u207b\u00b9. \u00b3He concentrations in samples deeper than \u223c100 meters are consistent with model-based estimates of depth-independent nucleogenic production from the capture by \u2076Li of neutrons produced by alpha particle reactions on light elements. Measurements in other subsurface samples indicate that muon-produced \u00b3He is prevalent across the Columbia Plateau. The penetration depth of muonogenic \u00b3He production is substantially deeper, and the ratio of muon- to spallation-produced \u00b3He is substantially lower, than found for other cosmogenic nuclides. Our results provide the first definitive empirical evidence for \u00b3He production by muons, which has several implications for quantifying the timing and rates of Earth surface change and interpreting He isotope ratios. Importantly, despite the low production rates, landforms in the Channeled Scablands, which were formed by incision of the Columbia River Basalt by the late-Pleistocene Missoula floods, have high concentrations of \u00b3He inherited from post-Miocene muon exposure. Hence \u00b3He production by muons must be considered, particularly when dating rapid erosional events in old bedrock. Our findings indicate samples with less than several tens of meters of shielding by overlying rock will contain cosmogenic \u00b3He that elevates \u00b3He/\u2074He ratios. Hence caution should be used when using \u00b3He/\u2074He ratios from samples at shallower depths to infer mantle sources of basalt.", "date": "2021-05-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "562", "publisher": "Elsevier", "pagerange": "Art. No. 116825", "id_number": "CaltechAUTHORS:20210517-123150941", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210517-123150941", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1529528" }, { "agency": "NSF", "grant_number": "EAR-1529110" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2021.116825", "primary_object": { "basename": "1-s2.0-S0012821X21000844-mmc1.xlsx", "url": "https://authors.library.caltech.edu/records/7rvb6-ytq31/files/1-s2.0-S0012821X21000844-mmc1.xlsx" }, "related_objects": [ { "basename": "1-s2.0-S0012821X21000844-mmc2.xlsx", "url": "https://authors.library.caltech.edu/records/7rvb6-ytq31/files/1-s2.0-S0012821X21000844-mmc2.xlsx" }, { "basename": "1-s2.0-S0012821X21000844-mmc3.xlsx", "url": "https://authors.library.caltech.edu/records/7rvb6-ytq31/files/1-s2.0-S0012821X21000844-mmc3.xlsx" } ], "resource_type": "article", "pub_year": "2021", "author_list": "Larsen, I. J.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/bmk75-a5e89", "eprint_id": 108479, "eprint_status": "archive", "datestamp": "2023-08-22 09:16:12", "lastmod": "2023-10-23 17:04:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Horton-F", "name": { "family": "Horton", "given": "F." } }, { "id": "Curtice-J", "name": { "family": "Curtice", "given": "J." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Kurz-Mark-D", "name": { "family": "Kurz", "given": "M. D." }, "orcid": "0000-0003-1745-2356" }, { "id": "Asimow-P-D", "name": { "family": "Asimow", "given": "P. D." }, "orcid": "0000-0001-6025-8925" }, { "id": "Treffkorn-Jonathan", "name": { "family": "Treffkorn", "given": "J." } }, { "id": "Boyes-Xenia-M", "name": { "family": "Boyes", "given": "X. M." }, "orcid": "0000-0002-6607-9757" } ] }, "title": "Primordial neon in high-\u00b3He/\u2074He Baffin Island olivines", "ispublished": "pub", "full_text_status": "restricted", "keywords": "primordial mantle; hotspot lavas; neon isotopes; noble gas geochemistry", "note": "\u00a9 2021 Elsevier B.V.\n\nReceived 7 October 2020, Revised 11 December 2020, Accepted 11 January 2021, Available online 25 January 2021.\n\nThe National Science Foundation (award #1911699) funded this research. The Woods Hole Oceanographic Institution (WHOI) Andrew W. Mellon Foundation Endowed Fund for Innovative Research and a National Geographic Society grant (#CP4-144R-18) supported fieldwork activities. The WHOI noble gas lab was supported by NSF OCE #1259218 and WHOI. We thank Maryse Mahy of the Parks Canada Nunavut Field Unit, the Qikiqtani Inuit Association, and the Nunavut Research Institute for their assistance and cooperation. Victoria Hooton provided invaluable help with mineral separation. Two anonymous reviews improved the manuscript.\n\nCRediT authorship contribution statement:\nF. Horton: Conceptualization, Formal analysis, Funding acquisition, Methodology, Supervision, Visualization, Writing \u2013 original draft. J. Curtice: Formal analysis, Investigation. K.A. Farley: Conceptualization, Funding acquisition, Investigation, Methodology, Resources, Supervision. M.D. Kurz: Investigation, Resources, Writing \u2013 review & editing. P.D. Asimow: Conceptualization, Funding acquisition, Supervision, Writing \u2013 review & editing. J. Treffkorn: Formal analysis, Investigation, Writing \u2013 original draft. X.M. Boyes: Formal analysis, Investigation.\n\nThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.", "abstract": "Paleocene basaltic lavas exposed on Baffin Island have the highest \u00b3He/\u2074He found in any terrestrial igneous rocks and potentially contain the most pristine primordial mantle material exposed on Earth's surface. By vacuum-crushing large (1\u20133 g) olivine mineral separates, we extracted enough magmatic gas to obtain the first coupled helium, neon, and argon isotopic compositions of Baffin Island lavas. The five Baffin Island olivine samples have \u00b3He/\u2074He ranging from 36.2 \u00b1 0.6 to 48.6 \u00b1 1.3 (1\u03c3) times the atmospheric ratio (Ra), overlapping with the highest known mantle values. Neon isotopic results fall on a mixing line between atmosphere and a high \u00b2\u2070Ne/\u00b2\u00b2Ne mantle endmember (with a maximum \u00b2\u2070Ne/\u00b2\u00b2Ne of 12.2). The slope of this mixing line is indistinguishable from that in subglacial Holocene glass from Iceland, but distinct from other hotspots and mid-ocean ridge basalt trends. This result supports the hypothesis that Baffin Island and Iceland lavas share a common high-\u00b3He/\u2074He mantle component, despite the fact that recent paleogeographic reconstructions place the Iceland hotspot far from Baffin Island at the time of eruption (61 Ma). Our results also demonstrate that high-\u00b3He/\u2074He mantle reservoirs have \u00b3He/\u00b2\u00b2Ne variability that either reflects ancient mantle heterogeneity or helium addition in the upper or lower mantle.", "date": "2021-03-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "558", "publisher": "Elsevier", "pagerange": "Art. No. 116762", "id_number": "CaltechAUTHORS:20210318-103515860", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210318-103515860", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1911699" }, { "agency": "Woods Hole Oceanographic Institution" }, { "agency": "Andrew W. Mellon Foundation" }, { "agency": "National Geographic Society", "grant_number": "CP4-144R-18" }, { "agency": "NSF", "grant_number": "OCE-1259218" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2021.116762", "resource_type": "article", "pub_year": "2021", "author_list": "Horton, F.; Curtice, J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/2bvrn-tg496", "eprint_id": 107095, "eprint_status": "archive", "datestamp": "2023-08-22 07:59:50", "lastmod": "2023-10-23 15:31:04", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sousa-F-J", "name": { "family": "Sousa", "given": "Francis J." }, "orcid": "0000-0003-1623-4023" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "A Framework for Evaluating Variation in (U-Th)/He Datasets", "ispublished": "pub", "full_text_status": "public", "keywords": "low temperature thermochronology; apatite (U-Th)/He; Bayesian MCMC thermal modeling; outliers; legitimate vs. illegitimate variation", "note": "\u00a9 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).\n\nReceived: 11 November 2020 / Revised: 6 December 2020 / Accepted: 8 December 2020 / Published: 10 December 2020. \n\n(This article belongs to the Section Mineral Geochemistry and Geochronology) \n\nThe Oregon State University Geomorphology Round Table is gratefully acknowledged for providing feedback on the intellectual framework of this project at an early stage. Lindsey Hedges is gratefully thanked for a lifetime of service to geochemistry. \n\nThis research received no external funding. \n\nAuthor Contributions. Conceptualization, F.J.S. and K.A.F.; Data curation, F.J.S.; Funding acquisition, F.J.S; Investigation, F.J.S.; Methodology, F.J.S.; Writing\u2014original draft, F.J.S; Writing\u2014review & editing, F.J.S. and K.A.F. All authors have read and agreed to the published version of the manuscript. \n\nThe authors declare no conflict of interest.\n\nPublished - minerals-10-01111-v2.pdf
", "abstract": "This paper presents a framework for evaluating variation in (U-Th)/He datasets. The framework is objective, repeatable, and based on compatibility of thermal histories derived from individual (U-Th)/He dates. The structure of this new method includes three fundamental steps. First, the allowable thermal history of each individual grain is quantitatively constrained with a model. Second, the thermal histories of all grains from a sample are visualized on the same axes. Third, the compatibility of the allowable thermal histories of each individual grain is evaluated. This allows a user to assess whether variation among single grain dates can plausibly be explained (referred to here as legitimate) or not (illegitimate). Additionally, this methodology allows for accurate representation of the impact that illegitimate variation has on the thermal history constraints of a sample. We demonstrate the application of this new framework using a variety of examples from the literature, as well as with synthetic data. Modeling presented here is executed using the modeling software QTQt (version 5.6.0) and the He diffusion kinetics based on the radiation damage accumulation and annealing model, but the framework is designed to be easily adaptable to any modeling software and diffusion parameters.", "date": "2020-12-10", "date_type": "published", "publication": "Minerals", "volume": "10", "number": "12", "publisher": "MDPI AG", "pagerange": "Art. No. 1111", "id_number": "CaltechAUTHORS:20201215-141037128", "issn": "2075-163X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201215-141037128", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.3390/min10121111", "primary_object": { "basename": "minerals-10-01111-v2.pdf", "url": "https://authors.library.caltech.edu/records/2bvrn-tg496/files/minerals-10-01111-v2.pdf" }, "resource_type": "article", "pub_year": "2020", "author_list": "Sousa, Francis J. and Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/a7qs5-xhq84", "eprint_id": 106988, "eprint_status": "archive", "datestamp": "2023-08-22 07:51:20", "lastmod": "2023-10-23 15:15:07", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Stack-Kathryn-M", "name": { "family": "Stack", "given": "Kathryn M." }, "orcid": "0000-0003-3444-6695" }, { "id": "Williams-Nathan-R", "name": { "family": "Williams", "given": "Nathan R." } }, { "id": "Calef-Fred-III", "name": { "family": "Calef", "given": "Fred, III" }, "orcid": "0000-0002-5132-3980" }, { "id": "Sun-Vivian-Z", "name": { "family": "Sun", "given": "Vivian Z." }, "orcid": "0000-0003-1480-7369" }, { "id": "Williford-Kenneth-H", "name": { "family": "Williford", "given": "Kenneth H." }, "orcid": "0000-0003-0633-408X" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "name": { "family": "Eide", "given": "Sigurd" } }, { "name": { "family": "Flannery", "given": "David" }, "orcid": "0000-0001-8982-496X" }, { "name": { "family": "Hughes", "given": "Cory" }, "orcid": "0000-0002-7061-1443" }, { "name": { "family": "Jacob", "given": "Samantha R." }, "orcid": "0000-0001-9950-1486" }, { "name": { "family": "Kah", "given": "Linda C." }, "orcid": "0000-0001-7172-2033" }, { "name": { "family": "Meyen", "given": "Forrest" }, "orcid": "0000-0002-0140-6411" }, { "name": { "family": "Molina", "given": "Antonio" }, "orcid": "0000-0002-5038-2022" }, { "name": { "family": "Nataf", "given": "Cathy Quantin" } }, { "name": { "family": "Rice", "given": "Melissa" }, "orcid": "0000-0002-8370-4139" }, { "name": { "family": "Russell", "given": "Patrick" } }, { "id": "Scheller-Eva-L", "name": { "family": "Scheller", "given": "Eva" }, "orcid": "0000-0002-9981-5802" }, { "name": { "family": "Seeger", "given": "Christina H." } }, { "id": "Abbey-William-J", "name": { "family": "Abbey", "given": "William J." } }, { "name": { "family": "Adler", "given": "Jacob B." }, "orcid": "0000-0002-4722-2909" }, { "name": { "family": "Amundsen", "given": "Hans" } }, { "name": { "family": "Anderson", "given": "Ryan B." }, "orcid": "0000-0003-4465-2871" }, { "name": { "family": "Angel", "given": "Stanley M." }, "orcid": "0000-0002-0328-0568" }, { "name": { "family": "Arana", "given": "Gorka" }, "orcid": "0000-0001-7854-855X" }, { "name": { "family": "Atkins", "given": "James" } }, { "name": { "family": "Barrington", "given": "Megan" } }, { "name": { "family": "Berger", "given": "Tor" } }, { "name": { "family": "Borden", "given": "Rose" }, "orcid": "0000-0002-2908-598X" }, { "name": { "family": "Boring", "given": "Beau" } }, { "name": { "family": "Brown", "given": "Adrian" } }, { "id": "Carrier-Brandi-L", "name": { "family": "Carrier", "given": "Brandi L." }, "orcid": "0000-0001-9943-7138" }, { "name": { "family": "Conrad", "given": "Pamela" }, "orcid": "0000-0001-5724-3343" }, { "name": { "family": "Dypvik", "given": "Henning" } }, { "name": { "family": "Fagents", "given": "Sarah A." }, "orcid": "0000-0002-3943-3335" }, { "name": { "family": "Gallegos", "given": "Zachary E." } }, { "name": { "family": "Garczynski", "given": "Brad" } }, { "name": { "family": "Golder", "given": "Keenan" }, "orcid": "0000-0002-4968-2239" }, { "name": { "family": "Gomez", "given": "Felipe" }, "orcid": "0000-0001-9977-7060" }, { "id": "Goreva-Yulia", "name": { "family": "Goreva", "given": "Yulia" } }, { "name": { "family": "Gupta", "given": "Sanjeev" } }, { "name": { "family": "Hamran", "given": "Svein-Erik" } }, { "name": { "family": "Hicks", "given": "Taryn" } }, { "name": { "family": "Hinterman", "given": "Eric D." } }, { "name": { "family": "Horgan", "given": "Briony N." }, "orcid": "0000-0001-6314-9724" }, { "name": { "family": "Hurowitz", "given": "Joel" } }, { "name": { "family": "Johnson", "given": "Jeffrey R." } }, { "name": { "family": "Lasue", "given": "Jeremie" }, "orcid": "0000-0001-9082-4457" }, { "id": "Kronyak-Rachel-E", "name": { "family": "Kronyak", "given": "Rachel E." }, "orcid": "0000-0002-2740-5660" }, { "id": "Liu-Yang-JPL", "name": { "family": "Liu", "given": "Yang" } }, { "name": { "family": "Madariaga", "given": "Juan Manuel" }, "orcid": "0000-0002-1685-6335" }, { "name": { "family": "Mangold", "given": "Nicolas" } }, { "name": { "family": "McClean", "given": "John" } }, { "name": { "family": "Miklusicak", "given": "Noah" } }, { "id": "Nunes-Daniel", "name": { "family": "Nunes", "given": "Daniel" }, "orcid": "0000-0002-0937-7176" }, { "name": { "family": "Rojas", "given": "Corrine" } }, { "name": { "family": "Runyon", "given": "Kirby" }, "orcid": "0000-0001-6361-6548" }, { "name": { "family": "Schmitz", "given": "Nicole" } }, { "name": { "family": "Scudder", "given": "Noel" } }, { "name": { "family": "Shaver", "given": "Emily" }, "orcid": "0000-0001-5176-448X" }, { "name": { "family": "SooHoo", "given": "Jason" }, "orcid": "0000-0003-1938-0720" }, { "name": { "family": "Spaulding", "given": "Russell" } }, { "name": { "family": "Stanish", "given": "Evan" } }, { "id": "Tamppari-Leslie-K", "name": { "family": "Tamppari", "given": "Leslie K." }, "orcid": "0000-0001-5124-6375" }, { "name": { "family": "Tice", "given": "Michael M." } }, { "name": { "family": "Turenne", "given": "Nathalie" } }, { "id": "Willis-Peter-A", "name": { "family": "Willis", "given": "Peter A." }, "orcid": "0000-0001-5394-1101" }, { "name": { "family": "Yingst", "given": "R. Aileen" }, "orcid": "0000-0002-0628-4265" } ] }, "title": "Photogeologic Map of the Perseverance Rover Field Site in Jezero Crater Constructed by the Mars 2020 Science Team", "ispublished": "pub", "full_text_status": "public", "keywords": "Mars; Perseverance; Rover; Jezero; Geologic mapping", "note": "\u00a9 2020 Springer. \n\nReceived 20 April 2020; Accepted 25 September 2020; Published 03 November 2020. \n\nThe authors would like to acknowledge the members of the Mars 2020 Council of Terrains, the United States Geological Survey Astrogeology Science Center, the scientists and engineers of the MRO HiRISE mission, and Frank Seelos for providing the base maps used in this study. We acknowledge Jeff Schroeder's assistance in the preparation of supplementary materials. Thanks to Shannon Cofield and Axel Noblet who worked with the lead author on preliminary mapping efforts in Jezero crater that preceded and informed the results of the Mars 2020 Science Team effort. Ken Edgett and Gilles Dromart provided helpful comments that improved this work. The authors would like to thank and acknowledge Tim Goudge and Brad Thomson for providing thoughtful, thorough, and helpful reviews of this manuscript. \n\nThis effort was carried out in part by named co-authors under a contract with the National Aeronautics and Space Administration. N. Schmitz acknowledges support from Deutsches Zentrum f\u00fcr Luft- und Raumfahrt German Aerospace Center. J. Lasue, N. Mangold, and C. Quantin-Nataf acknowledge support from Centre National d'Etudes Spatial (CNES). A. Molina acknowledges support from the \"MarsFirstWater,\" European Research Council, Consolidator Grant no. 818602 and the Agencia Estatal de Investigac\u00edon (AEI) project no. MDM-2017-0737 Unidad de Excelencia \"Mar\u00eda de Maeztu.\" T. Berger, H. Dypvik, S. Eide, and S.-E. Hamran acknowledge support from the University of Oslo and the Norwegian Defence Research Establishment. \n\nAuthor Contributions: \nConceptualization: K.M. Stack, K.H. Williford, K.A. Farley. \nMethodology: K.M. Stack, K.H. Williford, N.R. Williams, F. Calef III, V.Z. Sun. \nBasemap and data product production: N.R. Williams and F. Calef III. \nCAMP tool development and preparation: F. Calef III.\n\nMapping and unit descriptions: K.M. Stack, V.Z. Sun, K.H. Williford, S. Eide, D. Flannery, C. Hughes, S.R. Jacob, L.C. Kah, F. Meyen, A. Molina-Jurado, C.Q. Nataf, M. Rice, P. Russell, E. Scheller, C.H. Seeger, W.J. Abbey, J.B. Adler, H. Amundsen, R.B. Anderson, S.M. Angel, G. Arana, J. Atkins, B.L. Carrier, P. Conrad, M. Barrington, T. Berger, R. Borden, B. Boring, H. Dypvik, S.A. Fagents, Z.E. Gallegos, B. Garczynski, K. Golder, F. Gomez, Y. Goreva, S. Gupta, S.-E. Hamran, T. Hicks, E.D. Hinterman, B.N. Horgan, J. Hurowitz, J.R. Johnson, J. Lasue, Y. Liu, J.M. Madariaga, N. Mangold, J. McClean, N. Miklusicak, D. Nunes, C. Rojas, K. Runyon, N. Schmitz, N. Scudder, E. Shaver, J. SooHoo, R. Spaulding, E. Stanish, L.K. Tamppari, M.M. Tice, N. Turenne, P.A. Willis, A. Yingst. \nMap reconciliation: K.M. Stack, N.R. Williams, F. Calef III. \nWriting \u2013 original draft preparation: K.M. Stack, N.R. Williams, F. Calef III, V.Z. Sun. \nWriting \u2013 review and editing: K.M. Stack, N.R. Williams, R.E. Kronyak, A. Brown, P. Conrad, N. Mangold, C.H. Seeger, A. Yingst, P.A. Willis. \n\nThe Mars 2020 Mission. \n\nEdited by Kenneth A. Farley, Kenneth H. Williford and Kathryn M. Stack.\n\nSupplemental Material - 11214_2020_739_MOESM1_ESM.pdf
Supplemental Material - 11214_2020_739_MOESM2_ESM.tif
Supplemental Material - 11214_2020_739_MOESM3_ESM.zip
", "abstract": "The Mars 2020 Perseverance rover landing site is located within Jezero crater, a \u223c50 km diameter impact crater interpreted to be a Noachian-aged lake basin inside the western edge of the Isidis impact structure. Jezero hosts remnants of a fluvial delta, inlet and outlet valleys, and infill deposits containing diverse carbonate, mafic, and hydrated minerals. Prior to the launch of the Mars 2020 mission, members of the Science Team collaborated to produce a photogeologic map of the Perseverance landing site in Jezero crater. Mapping was performed at a 1:5000 digital map scale using a 25 cm/pixel High Resolution Imaging Science Experiment (HiRISE) orthoimage mosaic base map and a 1 m/pixel HiRISE stereo digital terrain model. Mapped bedrock and surficial units were distinguished by differences in relative brightness, tone, topography, surface texture, and apparent roughness. Mapped bedrock units are generally consistent with those identified in previously published mapping efforts, but this study's map includes the distribution of surficial deposits and sub-units of the Jezero delta at a higher level of detail than previous studies. This study considers four possible unit correlations to explain the relative age relationships of major units within the map area. Unit correlations include previously published interpretations as well as those that consider more complex interfingering relationships and alternative relative age relationships. The photogeologic map presented here is the foundation for scientific hypothesis development and strategic planning for Perseverance's exploration of Jezero crater.", "date": "2020-12", "date_type": "published", "publication": "Space Science Reviews", "volume": "216", "number": "8", "publisher": "Springer", "pagerange": "Art. No. 127", "id_number": "CaltechAUTHORS:20201209-145124835", "issn": "0038-6308", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201209-145124835", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" }, { "agency": "Deutsches Zentrum f\u00fcr Luft- und Raumfahrt (DLR)" }, { "agency": "Centre National d'\u00c9tudes Spatiales (CNES)" }, { "agency": "European Research Council (ERC)", "grant_number": "818602" }, { "agency": "Ministerio de Ciencia e Innovaci\u00f3n (MCINN)", "grant_number": "MDM-2017-0737" }, { "agency": "University of Oslo" }, { "agency": "Norwegian Defence Research Establishment" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1007/s11214-020-00739-x", "primary_object": { "basename": "11214_2020_739_MOESM1_ESM.pdf", "url": "https://authors.library.caltech.edu/records/a7qs5-xhq84/files/11214_2020_739_MOESM1_ESM.pdf" }, "related_objects": [ { "basename": "11214_2020_739_MOESM2_ESM.tif", "url": "https://authors.library.caltech.edu/records/a7qs5-xhq84/files/11214_2020_739_MOESM2_ESM.tif" }, { "basename": "11214_2020_739_MOESM3_ESM.zip", "url": "https://authors.library.caltech.edu/records/a7qs5-xhq84/files/11214_2020_739_MOESM3_ESM.zip" } ], "resource_type": "article", "pub_year": "2020", "author_list": "Stack, Kathryn M.; Williams, Nathan R.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3v6ra-94h43", "eprint_id": 106822, "eprint_status": "archive", "datestamp": "2023-08-22 07:50:20", "lastmod": "2023-10-20 23:50:13", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bralower-T-J", "name": { "family": "Bralower", "given": "T. J." }, "orcid": "0000-0002-3503-859X" }, { "name": { "family": "Cosmidis", "given": "J." }, "orcid": "0000-0003-3428-8447" }, { "name": { "family": "Fantle", "given": "M. S." } }, { "name": { "family": "Lowery", "given": "C. M." }, "orcid": "0000-0002-0101-4397" }, { "name": { "family": "Passey", "given": "B. H." } }, { "name": { "family": "Gulick", "given": "S. P. S." }, "orcid": "0000-0003-4740-9068" }, { "name": { "family": "Morgan", "given": "J. V." }, "orcid": "0000-0002-3832-2959" }, { "name": { "family": "Vajda", "given": "V." } }, { "name": { "family": "Whalen", "given": "M. T." } }, { "name": { "family": "Wittmann", "given": "A." }, "orcid": "0000-0001-7572-0801" }, { "name": { "family": "Artemieva", "given": "N." }, "orcid": "0000-0003-1347-016X" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K." }, "orcid": "0000-0002-7846-7546" }, { "name": { "family": "Goderis", "given": "S." }, "orcid": "0000-0002-6666-7153" }, { "name": { "family": "Hajek", "given": "E." }, "orcid": "0000-0001-9913-6298" }, { "name": { "family": "Heaney", "given": "P. J." } }, { "name": { "family": "Kring", "given": "D. A." }, "orcid": "0000-0002-3440-6282" }, { "name": { "family": "Lyons", "given": "S. L." }, "orcid": "0000-0003-4656-3434" }, { "name": { "family": "Rasmussen", "given": "C." }, "orcid": "0000-0001-9979-8224" }, { "name": { "family": "Sibert", "given": "E." }, "orcid": "0000-0003-0577-864X" }, { "name": { "family": "Rodr\u00edguez Tovar", "given": "F. J." } }, { "name": { "family": "Turner\u2010Walker", "given": "G." } }, { "name": { "family": "Zachos", "given": "J. C." }, "orcid": "0000-0001-8439-1886" }, { "name": { "family": "Carte", "given": "J." } }, { "name": { "family": "Chen", "given": "S. A." } }, { "name": { "family": "Cockell", "given": "C." } }, { "name": { "family": "Coolen", "given": "M." }, "orcid": "0000-0002-0417-920X" }, { "name": { "family": "Freeman", "given": "K. H." }, "orcid": "0000-0002-3350-7671" }, { "name": { "family": "Garber", "given": "J." } }, { "name": { "family": "Gonzalez", "given": "M." } }, { "name": { "family": "Gray", "given": "J. L." } }, { "name": { "family": "Grice", "given": "K." } }, { "name": { "family": "Jones", "given": "H. L." } }, { "name": { "family": "Schaefer", "given": "B." } }, { "name": { "family": "Smit", "given": "J." }, "orcid": "0000-0002-6070-4865" }, { "name": { "family": "Tikoo", "given": "S. M." }, "orcid": "0000-0001-9524-8284" } ] }, "title": "The Habitat of the Nascent Chicxulub Crater", "ispublished": "pub", "full_text_status": "public", "keywords": "K\u2010Pg boundary; Chicxulub; crater", "note": "\u00a9 2020 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. \n\nIssue Online: 24 November 2020; Version of Record online: 24 November 2020; Manuscript accepted: 28 July 2020; Manuscript revised: 16 July 2020; Manuscript received: 23 April 2020. \n\nExpedition 364 was jointly funded by the European Consortium for Ocean Research Drilling (ECORD) and ICDP, with contributions and logistical support from the Yucat\u00e1n State Government and Universidad Nacional Aut\u00f3noma de M\u00e9xico (UNAM). Research was funded by NSF\u2010OCE OCE 1736951 (to T. B. and K. H. F.), 1737351, 1737087, OCE 1736826, OCE 1737087, OCE 1737037, and OCE 1737199, and Post Expedition Awards from IODP to T. B., NERC grant NE/P005217/1 to J. V. M., and by the Swedish Research Council (VR) grant 2015\u20104264 to V. V. S. G. acknowledges the support by the Belgian Science Policy (BELSPO) and Research Foundation\u2010Flanders (FWO\u2010Vlaanderen). We thank the Expedition 364 captain and crew, drilling team, and technical staff who participated in shipboard and shore based activities, and the entire science party for their support. We acknowledge helpful discussions with Cristiano Colletini, Maureen Feineman, Lee Kump, Ron Shahar, and Andy Smye. We thank Holger Kuhlmann, Chad Broyles, and Phil Rumford for help with sampling; Julie Anderson and Wes Auker for assistance with the SEM; and Kat Crispin, Mark Fairchilds, and Tom Henderson with help with microscopy. We thank Drake Yarian, Elise Pelletier, Natalie Packard, Sarah Katz, Emily Beverly, Dana Brenner, and Ian Winkelstern for assistance with the clumped isotope and triple oxygen isotope analyses. We are very grateful to Mark Leckie and two anonymous reviewers for extremely helpful suggestions on an earlier version of the manuscript. This is UTIG Contribution #3590 and Center for Planetary Systems Habitability Contribution #0018. \n\nThe authors declare no conflicts of interest relevant to this study. \n\nData Availability Statement: The data that support the findings of this study are available in the PANGAEA database (https://www.pangaea.de/). This research used samples and data provided by IODP.\n\nPublished - 2020AV000208.pdf
Accepted Version - aga220050-sup-0004-2020av000208-first_revision_of_manuscript__accepted_.pdf
Submitted - aga220050-sup-0002-2020av000208-original_version_of_manuscript.pdf
Supplemental Material - aga220050-sup-0001-2020av000208-si.docx
Supplemental Material - aga220050-sup-0003-2020av000208-peer_review_history.pdf
Supplemental Material - aga220050-sup-0005-2020av000208-authors_response_to_peer_review_comments.pdf
Supplemental Material - aga220050-sup-0006-2020av000208-fs01.pdf
Supplemental Material - aga220050-sup-0007-2020av000208-fs02.pdf
Supplemental Material - aga220050-sup-0008-2020av000208-fs03.pdf
Supplemental Material - aga220050-sup-0009-2020av000208-fs04.pdf
Supplemental Material - aga220050-sup-0010-2020av000208-fs05.pdf
Supplemental Material - aga220050-sup-0011-2020av000208-fs06.pdf
Supplemental Material - aga220050-sup-0012-2020av000208-fs07.pdf
Supplemental Material - aga220050-sup-0013-2020av000208-fs08.pdf
Supplemental Material - aga220050-sup-0014-2020av000208-fs09.pdf
Supplemental Material - aga220050-sup-0015-2020av000208-fs10.pdf
Supplemental Material - aga220050-sup-0016-2020av000208-fs11.pdf
Supplemental Material - aga220050-sup-0017-2020av000208-fs12.pdf
Supplemental Material - aga220050-sup-0018-2020av000208-fs13.pdf
Supplemental Material - aga220050-sup-0019-2020av000208-fs14.pdf
", "abstract": "An expanded sedimentary section provides an opportunity to elucidate conditions in the nascent Chicxulub crater during the hours to millennia after the Cretaceous\u2010Paleogene (K\u2010Pg) boundary impact. The sediments were deposited by tsunami followed by seiche waves as energy in the crater declined, culminating in a thin hemipelagic marlstone unit that contains atmospheric fallout. Seiche deposits are predominantly composed of calcite formed by decarbonation of the target limestone during impact followed by carbonation in the water column. Temperatures recorded by clumped isotopes of these carbonates are in excess of 70\u00b0C, with heat likely derived from the central impact melt pool. Yet, despite the turbidity and heat, waters within the nascent crater basin soon became a viable habitat for a remarkably diverse cross section of the food chain. The earliest seiche layers deposited with days or weeks of the impact contain earliest Danian nannoplankton and dinocyst survivors. The hemipelagic marlstone representing the subsequent years to a few millennia contains a nearly monogeneric calcareous dinoflagellate resting cyst assemblage suggesting deteriorating environmental conditions, with one interpretation involving low light levels in the impact aftermath. At the same horizon, microbial fossils indicate a thriving bacterial community and unique phosphatic fossils including appendages of pelagic crustaceans, coprolites and bacteria\u2010tunneled fish bone, suggesting that this rapid recovery of the base of the food chain may have supported the survival of larger, higher trophic\u2010level organisms. The extraordinarily diverse fossil assemblage indicates that the crater was a unique habitat in the immediate impact aftermath, possibly as a result of heat and nutrients supplied by hydrothermal activity.", "date": "2020-12", "date_type": "published", "publication": "AGU Advances", "volume": "1", "number": "4", "publisher": "American Geophysical Union", "pagerange": "Art. No. e2020AV000208", "id_number": "CaltechAUTHORS:20201125-070002260", "issn": "2576-604X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201125-070002260", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "European Consortium for Ocean Research Drilling" }, { "agency": "International Continental Scientific Drilling Program" }, { "agency": "Yucat\u00e1n State Government" }, { "agency": "Universidad Nacional Aut\u00f3noma de M\u00e9xico (UNAM)" }, { "agency": "NSF", "grant_number": "OCE-1736951" }, { "agency": "NSF", "grant_number": "OCE-1737351" }, { "agency": "NSF", "grant_number": "OCE-1737087" }, { "agency": "NSF", "grant_number": "OCE-1736826" }, { "agency": "NSF", "grant_number": "OCE-1737087" }, { "agency": "NSF", "grant_number": "OCE-1737037" }, { "agency": "NSF", "grant_number": "OCE-1737199" }, { "agency": "Integrated Ocean Drilling Program" }, { "agency": "Natural Environment Research Council (NERC)", "grant_number": "NE/P005217/1" }, { "agency": "Swedish Research Council", "grant_number": "2015\u20104264" }, { "agency": "Belgian Federal Science Policy Office (BELSPO)" }, { "agency": "Fonds Wetenschappelijk Onderzoek (FWO)" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2020av000208", "primary_object": { "basename": "aga220050-sup-0004-2020av000208-first_revision_of_manuscript__accepted_.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0004-2020av000208-first_revision_of_manuscript__accepted_.pdf" }, "related_objects": [ { "basename": "aga220050-sup-0009-2020av000208-fs04.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0009-2020av000208-fs04.pdf" }, { "basename": "aga220050-sup-0010-2020av000208-fs05.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0010-2020av000208-fs05.pdf" }, { "basename": "aga220050-sup-0012-2020av000208-fs07.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0012-2020av000208-fs07.pdf" }, { "basename": "aga220050-sup-0018-2020av000208-fs13.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0018-2020av000208-fs13.pdf" }, { "basename": "aga220050-sup-0001-2020av000208-si.docx", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0001-2020av000208-si.docx" }, { "basename": "aga220050-sup-0002-2020av000208-original_version_of_manuscript.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0002-2020av000208-original_version_of_manuscript.pdf" }, { "basename": "aga220050-sup-0003-2020av000208-peer_review_history.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0003-2020av000208-peer_review_history.pdf" }, { "basename": "aga220050-sup-0005-2020av000208-authors_response_to_peer_review_comments.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0005-2020av000208-authors_response_to_peer_review_comments.pdf" }, { "basename": "aga220050-sup-0008-2020av000208-fs03.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0008-2020av000208-fs03.pdf" }, { "basename": "aga220050-sup-0011-2020av000208-fs06.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0011-2020av000208-fs06.pdf" }, { "basename": "aga220050-sup-0015-2020av000208-fs10.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0015-2020av000208-fs10.pdf" }, { "basename": "aga220050-sup-0017-2020av000208-fs12.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0017-2020av000208-fs12.pdf" }, { "basename": "2020AV000208.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/2020AV000208.pdf" }, { "basename": "aga220050-sup-0006-2020av000208-fs01.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0006-2020av000208-fs01.pdf" }, { "basename": "aga220050-sup-0007-2020av000208-fs02.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0007-2020av000208-fs02.pdf" }, { "basename": "aga220050-sup-0013-2020av000208-fs08.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0013-2020av000208-fs08.pdf" }, { "basename": "aga220050-sup-0014-2020av000208-fs09.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0014-2020av000208-fs09.pdf" }, { "basename": "aga220050-sup-0016-2020av000208-fs11.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0016-2020av000208-fs11.pdf" }, { "basename": "aga220050-sup-0019-2020av000208-fs14.pdf", "url": "https://authors.library.caltech.edu/records/3v6ra-94h43/files/aga220050-sup-0019-2020av000208-fs14.pdf" } ], "resource_type": "article", "pub_year": "2020", "author_list": "Bralower, T. J.; Cosmidis, J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/5ewr6-gbb09", "eprint_id": 102159, "eprint_status": "archive", "datestamp": "2023-08-22 05:16:52", "lastmod": "2023-10-19 23:54:08", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Miller-H-B-D", "name": { "family": "Miller", "given": "Hayden B. D." }, "orcid": "0000-0001-7305-928X" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Vasconcelos-P-M", "name": { "family": "Vasconcelos", "given": "Paulo M." } }, { "id": "Mostert-A", "name": { "family": "Mostert", "given": "Albert" } }, { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "John M." } } ] }, "title": "Intracrystalline site preference of oxygen isotopes in goethite: A single-mineral paleothermometer", "ispublished": "pub", "full_text_status": "public", "keywords": "paleoclimate; oxygen isotopes; goethite; iron oxide; geochronology; weathering", "note": "\u00a9 2020 Elsevier B.V. \n\nReceived 29 June 2019, Revised 21 January 2020, Accepted 16 March 2020, Available online 27 March 2020. \n\nThis work was supported by a gift from the Chair's Council of the Caltech Division of Geological and Planetary Sciences. Synthetic goethite precipitation and synchrotron XRD experiments were funded by Australian Research Council LP0455770, Australian Synchrotron Grant FI3897, and an Australian Postgraduate Award to Albert Mostert. We also thank James Hagadorn and the Denver Museum of Nature and Science for providing the two Pikes Peak samples (DMNH-14510 and DMNH-10029). We gratefully acknowledge comments by Crayton Yapp and two anonymous reviewers.\n\nSupplemental Material - 1-s2.0-S0012821X20301801-mmc1.pdf
Supplemental Material - 1-s2.0-S0012821X20301801-mmc2.pdf
", "abstract": "The crystal structure of goethite, FeO(OH), has two distinct oxygen sites, one with exclusively Fe-O bonds, the other with bonds to both iron and hydrogen. We developed a method to assess the oxygen isotope contrast between these sites by measuring both the bulk goethite and the oxygen released in the conversion of goethite to hematite. The method involves collecting the water released by dehydroxylation, fluorinating that population of extracted atoms, and measuring the resulting oxygen isotope composition (extracted \u03b4O\u00b9\u2078). Then, on a separate aliquot, all structural oxygen is fluorinated and measured (bulk \u03b4O\u00b9\u2078). Using synthetic goethite precipitates grown under controlled environmental conditions, we found significant temperature-dependent fractionation, \u03b5_(bulk-extracted)=(5.51\u00b10.26)\u00d7(10\u2076/T\u00b2)\u2212(44.5\u00b12.8); T in Kelvin). This intracrystalline fractionation forms the basis of a single-phase paleothermometer with an estimated uncertainty of \u223c2-3\u00b0C. The temperature dependence appears to be independent of the isotopic composition of the parent fluid from which the goethite formed and the pH of that fluid. This intracrystalline thermometer can be used to simultaneously determine the formation temperature of a goethite and the isotopic composition of the water from which it formed. Natural goethites analyzed with this technique yield geologically reasonable formation temperatures of between 15 and 41\u00b0C.", "date": "2020-06-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "539", "publisher": "Elsevier", "pagerange": "Art. No. 116237", "id_number": "CaltechAUTHORS:20200330-070628054", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200330-070628054", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Division of Geological and Planetary Sciences" }, { "agency": "Australian Research Council", "grant_number": "LP0455770" }, { "agency": "Australian Synchrotron", "grant_number": "FI3897" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2020.116237", "primary_object": { "basename": "1-s2.0-S0012821X20301801-mmc1.pdf", "url": "https://authors.library.caltech.edu/records/5ewr6-gbb09/files/1-s2.0-S0012821X20301801-mmc1.pdf" }, "related_objects": [ { "basename": "1-s2.0-S0012821X20301801-mmc2.pdf", "url": "https://authors.library.caltech.edu/records/5ewr6-gbb09/files/1-s2.0-S0012821X20301801-mmc2.pdf" } ], "resource_type": "article", "pub_year": "2020", "author_list": "Miller, Hayden B. D.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ye7v2-jnj06", "eprint_id": 103496, "eprint_status": "archive", "datestamp": "2023-08-22 04:55:19", "lastmod": "2023-10-20 16:25:59", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Taylor-S", "name": { "family": "Taylor", "given": "S." } }, { "id": "Lever-J-H", "name": { "family": "Lever", "given": "J. H." } }, { "id": "Burgess-K-D", "name": { "family": "Burgess", "given": "K. D." } }, { "id": "Stroud-Robert-M", "name": { "family": "Stroud", "given": "R. M." } }, { "id": "Brownlee-D-E", "name": { "family": "Brownlee", "given": "D. E." } }, { "id": "Nittler-Larry-R", "name": { "family": "Nittler", "given": "L. R." }, "orcid": "0000-0002-5292-6089" }, { "id": "Bardyn-A", "name": { "family": "Bardyn", "given": "A." } }, { "id": "Alexander-C-M-O'D", "name": { "family": "Alexander", "given": "C. M. O'D." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Treffkorn-Jonathan", "name": { "family": "Treffkorn", "given": "J." } }, { "id": "Messenger-S", "name": { "family": "Messenger", "given": "S." } }, { "id": "Wozniakiewicz-P-J", "name": { "family": "Wozniakiewicz", "given": "P. J." } } ] }, "title": "Sampling interplanetary dust from Antarctic air", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2020 The Meteoritical Society. \n\nIssue Online: 15 July 2020; Version of Record online: 27 May 2020; Manuscript accepted: 24 March 2020; Manuscript revised: 23 March 2020; Manuscript received: 30 December 2019. \n\nWe thank Dr. Jeff Grossman, NASA's Emerging Worlds program manager, for funding this project and for added support provided by Dr. Scott Borg, NSF's Antarctic Program manager. We thank our research associates Adam West (2017), Ta\u2010Lee Shue (2018), and Sheryl Seagraves (2019) who conscientiously monitored the operation of the collector and changed out the filters. Many people at South Pole helped to make this project a reality but a special thanks to Leah Street, our NSF science support coordinator and to Dan McCreight, our NSF logistics coordinator. We also thank our students Amanda Pinson and Summer Christenson from Dartmouth College and David Bour, an NRL SEAP student intern. Lastly, we thank Dr. Hope Ishii and an anonymous reviewer who provided comments that improved the paper. The authors have no conflict of interests that could affect the results presented in this paper.\n\nPublished - maps.13483.pdf
Supplemental Material - maps13483-sup-0001-appendixs1.docx
Supplemental Material - maps13483-sup-0002-appendixs2.pdf
Supplemental Material - maps13483-sup-0003-appendixs3-a.pdf
Supplemental Material - maps13483-sup-0004-appendixs4.pdf
", "abstract": "We built a collector to filter interplanetary dust particles (IDPs) larger than 5 \u03bcm from the clean air at the Amundsen Scott South Pole station. Our sampling strategy used long duration, continuous dry filtering of near\u2010surface air in place of short duration, high\u2010speed impact collection on flags flown in the stratosphere. We filtered ~10\u2077 m\u00b3 of clean Antarctic air through 20 cm diameter, 3 \u00b5m filters coupled to a suction blower of modest power consumption (5\u20136 kW). Our collector ran continuously for 2 years and yielded 41 filters for analyses. Based on stratospheric concentrations, we predicted that each month's collection would provide 300\u2013900 IDPs for analysis. We identified 19 extraterrestrial (ET) particles on the 66 cm\u00b2 of filter examined, which represented ~0.5% of the exposed filter surfaces. The 11 ET particles larger than 5 \u00b5m yield about a fifth of the expected flux based on >5 \u00b5m stratospheric ET particle flux. Of the 19 ET particles identified, four were chondritic porous IDPs, seven were FeNiS beads, two were FeNi grains, and six were chondritic material with FeNiS components. Most were <10 \u00b5m in diameter and none were cluster particles. Additionally, a carbon\u2010rich candidate particle was found to have a small \u00b9\u2075N isotopic enrichment, supporting an ET origin. Many other candidate grains, including chondritic glasses and C\u2010rich particles with Mg and Si and FeS grains, require further analysis to determine if they are ET. The vast majority of exposed filter surfaces remain to be examined.", "date": "2020-05", "date_type": "published", "publication": "Meteoritics and Planetary Science", "volume": "55", "number": "5", "publisher": "Meteoritical Society", "pagerange": "1128-1145", "id_number": "CaltechAUTHORS:20200527-131917889", "issn": "1086-9379", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200527-131917889", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "15\u2010EW15\u20102\u2010009" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/maps.13483", "primary_object": { "basename": "maps.13483.pdf", "url": "https://authors.library.caltech.edu/records/ye7v2-jnj06/files/maps.13483.pdf" }, "related_objects": [ { "basename": "maps13483-sup-0001-appendixs1.docx", "url": "https://authors.library.caltech.edu/records/ye7v2-jnj06/files/maps13483-sup-0001-appendixs1.docx" }, { "basename": "maps13483-sup-0002-appendixs2.pdf", "url": "https://authors.library.caltech.edu/records/ye7v2-jnj06/files/maps13483-sup-0002-appendixs2.pdf" }, { "basename": "maps13483-sup-0003-appendixs3-a.pdf", "url": "https://authors.library.caltech.edu/records/ye7v2-jnj06/files/maps13483-sup-0003-appendixs3-a.pdf" }, { "basename": "maps13483-sup-0004-appendixs4.pdf", "url": "https://authors.library.caltech.edu/records/ye7v2-jnj06/files/maps13483-sup-0004-appendixs4.pdf" } ], "resource_type": "article", "pub_year": "2020", "author_list": "Taylor, S.; Lever, J. H.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/kg62w-6g376", "eprint_id": 101056, "eprint_status": "archive", "datestamp": "2023-08-22 04:26:24", "lastmod": "2023-10-19 22:24:04", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Treffkorn-J", "name": { "family": "Treffkorn", "given": "J." } }, { "id": "Hamilton-D-C", "name": { "family": "Hamilton", "given": "D." } } ] }, "title": "Isobar-free neon isotope measurements of flux-fused potential reference minerals on a Helix-MC-Plus^(10K) mass spectrometer", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2020 Elsevier. \n\nReceived 4 September 2019, Revised 12 January 2020, Accepted 31 January 2020, Available online 1 February 2020. \n\nThe authors thank Dan Barfod and two anonymous reviewers for helpful comments on this manuscript. \n\nThe authors declare the following financial interests/personal relationships which may be considered as potential competing interests:\nAuthor Doug Hamilton is employed by ThermoFisher the manufacturer of the mass spectrometer described in this manuscript.", "abstract": "This work presents new analytical techniques for extraction and analysis of neon from a suite of different mineral phases, including quartz, pyroxene, hematite, apatite, zircon, topaz, and fluorite. Neon was quantitatively extracted at 1100\u202f\u00b0C from all of these minerals using an in-vacuum lithium borate-flux fusion technique. Evolved neon was purified using a cryogenic method capable of separating Ne from He present in abundances ~8 orders of magnitude higher, typical of samples carrying nucleogenic/radiogenic noble gases. The purified neon was measured on a Helix-MC-Plus^(10K) mass spectrometer that permits isobar-free measurement of all three neon isotopes. When operated at its highest mass resolving power (MRP) of ~10,300, the shoulder representing solely \u00b2\u00b2Ne on the low mass-side of the \u00b2\u00b2Ne-CO\u2082\u207a\u00b2 doublet is wide enough to permit measurement of isobar free \u00b2\u00b2Ne. Operating in this mode comes with the penalty of a 50% reduction in neon sensitivity. Coupled with a mathematical isobar-stripping method, this approach excludes 99.5% of the CO\u2082\u207a\u00b2 while still collecting >99% of the \u00b2\u00b2Ne beam. Routine edge-centering on the dynamic CO\u2082\u207a\u00b2 peak prior to introduction of a sample permits rapid and robust relocation of the desired measure point in the mass spectrum. \n\nCosmogenic \u00b2\u00b9Ne and \u00b2\u00b2Ne concentrations obtained using these methods on the Cronus-A quartz and Cronus-P pyroxene international reference materials are in excellent agreement with previous work or expectations. Similarly, the concentration of nucleogenic \u00b2\u00b9Ne and \u00b2\u00b2Ne in Durango apatite and the CIT hematite standard agree well with previous work. Durango apatite has notable heterogeneity in neon concentrations, consistent with previous observations of heterogeneous He, U and Th concentrations in this apatite. Nucleogenic neon concentrations are also presented for previously unstudied minerals including a Sri Lanka zircon (SLC), a topaz from the Imperial Topaz mine in Brazil (ITP1), and a fluorite (W-90) from New Hampshire. Taken together this set of potential reference minerals and the associated dataset provide a starting point for intercalibration among multiple mineral phases carrying \u00b2\u00b9Ne and \u00b2\u00b2Ne of cosmogenic or nucleogenic origin.", "date": "2020-03-30", "date_type": "published", "publication": "Chemical Geology", "volume": "537", "publisher": "Elsevier", "pagerange": "Art. No. 119487", "id_number": "CaltechAUTHORS:20200203-092720795", "issn": "0009-2541", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200203-092720795", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.chemgeo.2020.119487", "resource_type": "article", "pub_year": "2020", "author_list": "Farley, K. A.; Treffkorn, J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/snrdx-mk591", "eprint_id": 100225, "eprint_status": "archive", "datestamp": "2023-08-22 03:58:38", "lastmod": "2023-10-18 19:11:36", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Monteiro-H-S", "name": { "family": "Monteiro", "given": "H. S." }, "orcid": "0000-0002-3797-1869" }, { "id": "Vasconcelos-P-M-P", "name": { "family": "Vasconcelos", "given": "P. M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "\u00c1vila-J-N", "name": { "family": "\u00c1vila", "given": "J. N." } }, { "id": "Miller-H-B-D", "name": { "family": "Miller", "given": "H. B. D." } }, { "id": "Holden-P", "name": { "family": "Holden", "given": "P." } }, { "id": "Ireland-T-R", "name": { "family": "Ireland", "given": "T. R." } } ] }, "title": "Protocols for in situ measurement of oxygen isotopes in goethite by ion microprobe", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Goethite; SHRIMP-SI; (UTh)/He; Oxygen isotopes; Ion microprobe; Matrix effect", "note": "\u00a9 2019 Published by Elsevier B.V. \n\nReceived 16 December 2018, Revised 27 November 2019, Accepted 28 November 2019, Available online 6 December 2019. \n\nWe thank present and past colleagues from Vale, particularly Carlos Monte Lopes, Luzimar Rego, Clovis Maurity, Paulo S\u00e9rgio Ribeiro, Fernando Greco, Fernando Martins, Henrile Meireles, Carlos Augusto de Medeiros Filho, Augusto Kishida, and Felipe Porto for field support in the Caraj\u00e1s region. We thank Carlos Spier, then at MBR, for field support in the Quadril\u00e1tero Ferr\u00edfero. We thank UQ-CMM staff for help during microanalysis. We thank Mr. Llyam White for carrying additional laser fluorination analyses. This project was funded by the Australian Research Council (ARC Discovery DP160104988) grant to Paulo Vasconcelos and Kenneth Farley, Australian Research Council (ARC LP1401008005) grant to Gordon Southam et al., Australian Research Council (ARC LE0560868) grant to Trevor Ireland, and the Brazilian Research Council (CNPq) Science Without Borders scholarship to Hevelyn Monteiro. \n\nThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.", "abstract": "We present protocols for high-spatial resolution measurement of oxygen isotope ratios of goethite (\u03b1-FeOOH) with the Sensitive High Mass Resolution Ion Microprobe \u2013 Stable Isotopes (SHRIMP-SI) and propose a natural sample as a potential goethite reference material (RM) for ion microprobe analysis. We assess the effects of goethite chemical composition, crystallographic orientation, and texture on the accuracy and repeatability of SHRIMP-SI \u03b4\u00b9\u2078O (\u03b4\u00b9\u2078O_(SIMS)) results. Synthetic goethites evaluated as potential \u03b4\u00b9\u2078O_(SIMS) RM are powdery, porous, and finely crystalline; they do not yield repeatable results. A dense colloform goethite from the Cap\u00e3o topaz mine, Minas Gerais, Brazil, fulfills major prerequisites: it is stoichiometrically relatively pure, yields repeatable oxygen isotope results, and occurs in abundance to produce a RM for long-term use. We use an average laser fluorination \u03b4\u00b9\u2078O_(LF-VSMOW) value of \u221217.3\u202f\u00b1\u202f0.3\u2030 (1SD) obtained for five aliquots of this RM to normalize all \u03b4\u00b9\u2078O_(SIMS) measurements. Multiple \u03b4\u00b9\u2078O_(SIMS) analyses of a large fragment of the Cap\u00e3o L4 (CL4) RM analyzed in three different runs yield an overall repeatability of \u221217.3\u202f\u00b1\u202f0.5\u2030 (2SD, n\u202f=\u202f294) for all three runs combined. Natural variability and crystal orientation effects are the main reasons for the excess spread of the \u03b4\u00b9\u2078O_(SIMS) results compared to the spot internal precision (ca. 0.2\u2030). All \u03b4\u00b9\u2078O_(SIMS) analyses (n\u202f=\u202f1027) in various aliquots of CL4, randomly oriented and analyzed in 26 sessions during eight distinct runs, yield an overall repeatability of \u00b10.7\u2030 (2SD), confirming that CL4 is a suitable SIMS RM. After ascertaining its suitability as a RM, we used CL4 to standardize analyses of other natural goethite samples with the SHRIMP-SI and compared \u03b4\u00b9\u2078O_(SIMS) and laser fluorination results to test the relationship between natural properties (e.g., porosity, minor elements substituting for Fe), preparation procedures (e.g., polish and relief), instrument conditions, and the overall precision and accuracy of the SIMS analyses. Samples containing minor elements substituting for Fe (e.g., Al, Mn, Cu, Zn, etc.) or as contaminants (e.g., Si, P) require significant matrix corrections. Because we could not find homogenous natural goethite samples showing a large range in metal concentrations, we extrapolate our calibration curves beyond the composition of our calibration goethite samples. \u03b4\u00b9\u2078O_(SIMS) results corrected for instrument mass fractionation (using CL4) and compositionally dependent matrix effects (using several calibration goethites of known elemental composition) are less precise but statistically indistinguishable from their laser fluorination results. However, porous samples are unsuitable for SHRIMP-SI \u03b4\u00b9\u2078O analysis. Dense colloform samples yield repeatable results for individual growth bands, showing that the high spatial resolution, moderate precision, and speed of analysis of the SHRIMP-SI can resolve variations in oxygen isotope composition acquired during sample growth. (U Th)/He geochronology of equivalent aliquots from the same goethite samples reveal that the combination of the two methods permits the extraction of temporal variation in the isotopic compositions of meteoric solutions in the geological past.", "date": "2020-02-05", "date_type": "published", "publication": "Chemical Geology", "volume": "533", "publisher": "Elsevier", "pagerange": "Art. No. 119436", "id_number": "CaltechAUTHORS:20191206-112007657", "issn": "0009-2541", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191206-112007657", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Australian Research Council", "grant_number": "DP160104988" }, { "agency": "Australian Research Council", "grant_number": "LP1401008005" }, { "agency": "Australian Research Council", "grant_number": "LE0560868" }, { "agency": "Conselho Nacional de Desenvolvimento Cient\u00edfico e Tecnol\u00f3gico (CNPq)" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.chemgeo.2019.119436", "resource_type": "article", "pub_year": "2020", "author_list": "Monteiro, H. S.; Vasconcelos, P. M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/n3qyx-kf341", "eprint_id": 101652, "eprint_status": "archive", "datestamp": "2023-08-22 03:52:44", "lastmod": "2023-10-23 16:14:16", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Martin-P-E", "name": { "family": "Martin", "given": "Peter E." }, "orcid": "0000-0003-4243-2090" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Archer-P-D-Jr", "name": { "family": "Archer", "given": "P. Douglas Jr." } }, { "id": "Hogancamp-J-V", "name": { "family": "Hogancamp", "given": "Joanna V." }, "orcid": "0000-0003-2556-8586" }, { "id": "Siebach-K-L", "name": { "family": "Siebach", "given": "Kirsten L." }, "orcid": "0000-0002-6628-6297" }, { "id": "Grotzinger-J-P", "name": { "family": "Grotzinger", "given": "John P." }, "orcid": "0000-0001-9324-1257" }, { "id": "McLennan-S-M", "name": { "family": "McLennan", "given": "Scott M." }, "orcid": "0000-0003-4259-7178" } ] }, "title": "Reevaluation of Perchlorate in Gale Crater Rocks Suggests Geologically Recent Perchlorate Addition", "ispublished": "pub", "full_text_status": "public", "keywords": "Mars; perchlorate; chlorine; evolved gas analysis; Curiosity; Sample Analysis at Mars", "note": "\u00a9 2020 American Geophysical Union. \n\nReceived 7 AUG 2019; Accepted 16 JAN 2020; Accepted article online 30 JAN 2020. \n\nWe thank Brad Sutter for many thoughtful and spirited debates which improved this manuscript. We also thank the SAM and Curiosity teams for their support in rover operations, without which this work would not be possible. SAM data are available on the Planetary Data System (PDS; pds\u2010geosciences.wustl.edu/missions/msl/sam.htm). Additional data used in this study are available on the CaltechDATA repository at https://doi.org/10.22002/D1.1299. Funding was provided by NASA.\n\nPublished - Martin_et_al-2020-Journal_of_Geophysical_Research__Planets.pdf
Supplemental Material - jgre21292-sup-0001-2019je006156-si.docx
", "abstract": "Perchlorate (ClO\u2084\u207b) was discovered in Martian soil by the Phoenix lander, with important implications for potential Martian biology, photochemistry, aqueous chemistry, and the chlorine cycle on Mars. Perchlorate was subsequently reported in both loose sediment and bedrock samples analyzed by the Sample Analysis at Mars instrument onboard the Curiosity rover in Gale crater based on a release of O\u2082 at 200\u2013500\u00b0C. However, the continually wet paleoenvironment recorded by the sedimentary rocks in Gale crater was not conducive to the deposition of highly soluble salts. Furthermore, the preservation of ancient perchlorate to the modern day is unexpected due to its low thermodynamic stability and radiolytic decomposition associated with its long exposure to radioactivity and cosmic radiation. We therefore investigate alternative sources of O\u2082 in Sample Analysis at Mars analyses including superoxides, sulfates, nitrate, and nanophase iron and manganese oxides. Geochemical evidence and oxygen release patterns observed by Curiosity are inconsistent with each of these alternatives. We conclude that perchlorate is indeed the most likely source of the detected O2 release at 200\u2013500\u00b0C, but contend that it is unlikely to be ancient. Rather than being associated with the lacustrine or early diagenetic environment, the most likely origin of perchlorate in the bedrock is late stage addition by downward percolation of water through rock pore space during transient wetting events in the Amazonian. The conclusion that the observed perchlorate in Gale crater is most likely Amazonian suggests the presence of recent liquid water at the modern surface.", "date": "2020-02", "date_type": "published", "publication": "Journal of Geophysical Research. Planets", "volume": "125", "number": "2", "publisher": "American Geophysical Union", "pagerange": "Art. No. e2019JE006156", "id_number": "CaltechAUTHORS:20200302-130340431", "issn": "2169-9097", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200302-130340431", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2019je006156", "primary_object": { "basename": "Martin_et_al-2020-Journal_of_Geophysical_Research__Planets.pdf", "url": "https://authors.library.caltech.edu/records/n3qyx-kf341/files/Martin_et_al-2020-Journal_of_Geophysical_Research__Planets.pdf" }, "related_objects": [ { "basename": "jgre21292-sup-0001-2019je006156-si.docx", "url": "https://authors.library.caltech.edu/records/n3qyx-kf341/files/jgre21292-sup-0001-2019je006156-si.docx" } ], "resource_type": "article", "pub_year": "2020", "author_list": "Martin, Peter E.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/5ewbb-51h36", "eprint_id": 99665, "eprint_status": "archive", "datestamp": "2023-08-22 03:39:49", "lastmod": "2023-10-18 18:38:40", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Balbas-A-M", "name": { "family": "Balbas", "given": "A. M." }, "orcid": "0000-0002-4855-3507" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Constraining in situ cosmogenic nuclide paleo-production rates using sequential lava flows during a paleomagnetic field strength low", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Cosmogenic Nuclides; Paleomagnetism; Matuyama-Bruhnes; Magnetic Reversal; Helium-3; production rates; cosmic rays", "note": "\u00a9 2019 Elsevier B.V. \n\nReceived 6 August 2019, Revised 26 September 2019, Accepted 31 October 2019, Available online 1 November 2019. \n\nWe thank Kevin Konrad for providing the in vacuo crushed olivine results and helpful discussions. This work was supported by an NSF AGEP Fellowship for A. Balbas and benefitted greatly from discussions with Peter Clark, Joe Stoner, Brendan Reilly, Ed Brook and Anthony Koppers. We thank two anonymous reviewers for helpful comments that improved the manuscript. \n\nDeclaration of Competing Interest: None.", "abstract": "The geomagnetic field prevents a portion of incoming cosmic rays from reaching Earth's atmosphere. During magnetic reversals and excursions, the field strength can decrease by up to 90% relative to the modern-day value. During such anomalies, cosmic ray bombardment to Earth's atmosphere increases as evident from atmospheric \u00b9\u2070Be anomalies recorded in sediment and ice cores. However, how the flux of cosmic rays to Earth's surface varies during such geomagnetic anomalies is not well constrained. We measured fossil cosmogenic \u00b3He in olivine from the tops of two pairs of \u2074\u2070Ar/\u00b3\u2079Ar age-dated Tahitian lava flows that erupted during the Matuyama-Brunhes reversal precursor event. We corrected these raw values for the diffusive loss of helium caused by heating from the overlying flow with a diffusion model using cooling rates and maximum temperature conditions based on field measurements of active lava flows from Kilauea, Hawaii. We assume the maximum temperature suggested by field measurements and thus present a limiting case for the highest diffusive loss corrections and thus the highest paleo-production rates. Based on paleomagnetic field strength reconstructions and scaling factor models, the upper limits of the corrected in situ 3He paleo-production rates (100\u2009\u00b1\u200923, 144\u2009\u00b1\u200935 atoms g\u207b\u00b9 a\u207b\u00b9) are in agreement with those expected during the period of a geomagnetic field strength low when these flow tops were exposed. However, the more plausible contact temperatures (<700\u00b0C maximum temperature in diffusion model) are associated with diffusion corrected paleo-production rates lower than those predicted by scalar models. This potential underestimation is likely a function of changes in local non-dipole field components, atmospheric density and/or an overestimation of the dipole field strength reduction during the M-B precursor event.", "date": "2020-01-20", "date_type": "published", "publication": "Chemical Geology", "volume": "532", "publisher": "Elsevier", "pagerange": "Art. No. 119355", "id_number": "CaltechAUTHORS:20191105-094210699", "issn": "0009-2541", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191105-094210699", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.chemgeo.2019.119355", "resource_type": "article", "pub_year": "2020", "author_list": "Balbas, A. M. and Farley, K. A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/yafvp-g7h97", "eprint_id": 99760, "eprint_status": "archive", "datestamp": "2023-08-22 03:39:56", "lastmod": "2023-10-18 18:45:29", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hofmann-F", "name": { "family": "Hofmann", "given": "Florian" } }, { "id": "Treffkorn-J", "name": { "family": "Treffkorn", "given": "Jonathan" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "U-loss associated with laser-heating of hematite and goethite in vacuum during (U-Th)/He dating and prevention using high O\u2082 partial pressure", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Hematite; Goethite; (U-Th)/He dating; single-aliquot; geochronology", "note": "\u00a9 2019 Elsevier B.V. \n\nReceived 23 June 2019, Revised 20 October 2019, Accepted 25 October 2019, Available online 9 November 2019. \n\nWe thank Hayden Miller for providing samples, sharing data, and constructive discussions. Assistance with ATR-FTIR spectroscopy from George Rossman is greatly appreciated. We thank Nathan Dalleska for his help with ICP-MS at the Environmental Analysis Center at Caltech. Peter Reiners and two anonymous reviewers are thanked for their insightful comments, which helped to improve this manuscript.", "abstract": "Single-aliquot (U-Th)/He dating of hematite has been used to study iron-oxide precipitation in various environments, but we show there is an important challenge to the method: highly retentive hematite samples require temperatures of > 1000\u00b0 C to be completely degassed, whereas the temperature for major U-loss is \u223c980\u00b0 C. This leads to erroneously high (U-Th)/He ages. Through the analysis of U, Th, and Sm of hematite and goethite samples, we show the degree of U-loss at this temperature and demonstrate that prolonged heating at temperatures of 950\u00b0 C can lead to U-loss. We show that loss of U in goethite and hematite samples is associated with phase change from hematite to magnetite as Fe is reduced. The onset temperature of vacuum reduction of hematite can be increased from about 800-900\u00b0 C in vacuum to approximately 1250\u00b0 C in an oxygen partial pressure of 100 mbar. We show that samples can be outgassed to extract helium at 1150\u00b0 C without U-loss in an O\u2082-rich atmosphere during heating, which does not increase the analytical blanks. We describe our implementation and automation of the procedure. An average age calculated on a reference hematite sample from replicate aliquots (n=12), which were analyzed using this procedure, has a relative uncertainty of 2% (1\u03c3), and is within uncertainty of the previously measured two-aliquot age. We suggest this O\u2082 degassing procedure as a way to precisely and reproducibly determine single-aliquot hematite and goethite (U-Th)/He ages.", "date": "2020-01-20", "date_type": "published", "publication": "Chemical Geology", "volume": "532", "publisher": "Elsevier", "pagerange": "Art. No. 119350", "id_number": "CaltechAUTHORS:20191111-071935108", "issn": "0009-2541", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191111-071935108", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.chemgeo.2019.119350", "resource_type": "article", "pub_year": "2020", "author_list": "Hofmann, Florian; Treffkorn, Jonathan; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/rb0d5-any88", "eprint_id": 98227, "eprint_status": "archive", "datestamp": "2023-08-22 03:00:09", "lastmod": "2023-10-18 17:10:09", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Larsen-I-J", "name": { "family": "Larsen", "given": "Isaac J." }, "orcid": "0000-0003-3094-4830" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Lamb-M-P", "name": { "family": "Lamb", "given": "Michael P." }, "orcid": "0000-0002-5701-0504" } ] }, "title": "Cosmogenic ^3He production rate in ilmenite and the redistribution of spallation ^3He in fine-grained minerals", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2019 Elsevier Ltd. \n\nReceived 22 January 2019, Accepted 19 August 2019, Available online 26 August 2019. \n\nWe thank George Rossman, Chi Ma, and Michael Jercinovic for assistance with mineral characterization and Lindsey Hedges, Ryan McKeon, Elliot Simon, and Derek Berman for laboratory assistance. We thank Ben Mackey for making his SRP samples and his analyses of He in olivine available and Willy Amidon for sharing and providing guidance in using his code to model ^3He production via neutron capture. We thank Pieter Vermeesch and two anonymous reviewers for constructive comments. \n\nThis research was supported by a collaborative NSF award (1529528, 1529110) to I.J.L. K.A.F., and M.P.L. and NASA grant NNX13AM83G to MPL.", "abstract": "Cosmogenic nuclide surface exposure dating and erosion rate measurements in basaltic landscapes rely primarily on measurement of ^3He in olivine or pyroxene. However, geochemical investigations using ^3He have been impossible in the substantial fraction of basalts that lack separable olivine or pyroxene crystals, or where such crystals were present, but have been chemically weathered. Fine-textured basalts often contain small grains of ilmenite, a weathering-resistant mineral that is a target for cosmogenic ^3He production with good He retention and straightforward mineral separation, but with a poorly constrained production rate. Here we empirically calibrate the cosmogenic ^3He production rate in ilmenite by measuring ^3He concentrations in basalts with fine-grained (\u223c20\u202f\u03bcm cross-section) ilmenite and co-existing pyroxene or olivine from the Columbia River and Snake River Plain basalt provinces in the western United States. The concentration ratio of ilmenite to pyroxene and olivine is 0.78\u202f\u00b1\u202f0.02, yielding an apparent cosmogenic ^3He production rate of 93.6\u202f\u00b1\u202f7.7 atom g^(\u22121) yr^(\u22121) that is 20\u201330% greater than expected from prior theoretical and empirical estimates for compositionally similar minerals. The production rate discrepancy arises from the high energy with which cosmic ray spallation reactions emit tritium and ^3He and the associated long stopping distances that cause them to redistribute within a rock. Fine-grained phases with low cosmogenic ^3He production rates, like ilmenite, will have anomalously high production rates owing to net implantation of ^3He from the surrounding, higher ^3He production rate, matrix. Semi-quantitative modeling indicates implantation of spallation ^3He increases with decreasing ilmenite grain size, leading to production rates that exceed those in a large grain by \u223c10% when grain radii are <150\u202f\u03bcm. The modeling predicts that for the ilmenite grain size in our samples, implantation causes production rates to be \u223c20% greater than expected for a large grain, and within uncertainty resolves the discrepancy between our calibrated production rate, theory, and rates from previous work. The redistribution effect is maximized when the host rock and crystals differ substantially in mean atomic number, as they do between whole-rock basalt and ilmenite.", "date": "2019-11-15", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "265", "publisher": "Elsevier", "pagerange": "19-31", "id_number": "CaltechAUTHORS:20190826-101739298", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-101739298", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1529528" }, { "agency": "NSF", "grant_number": "EAR-1529110" }, { "agency": "NASA", "grant_number": "NNX13AM83G" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2019.08.025", "resource_type": "article", "pub_year": "2019", "author_list": "Larsen, Isaac J.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ctk15-qwn54", "eprint_id": 97660, "eprint_status": "archive", "datestamp": "2023-08-22 02:50:01", "lastmod": "2023-10-18 16:11:14", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Cohen-B-A", "name": { "family": "Cohen", "given": "Barbara A." }, "orcid": "0000-0001-5896-5903" }, { "id": "Malespin-C-A", "name": { "family": "Malespin", "given": "Charles A." }, "orcid": "0000-0002-5852-5016" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Martin-P-E", "name": { "family": "Martin", "given": "Peter E." }, "orcid": "0000-0003-4243-2090" }, { "id": "Cho-Yuichiro", "name": { "family": "Cho", "given": "Yuichiro" }, "orcid": "0000-0003-2749-2204" }, { "id": "Mahaffy-P-R", "name": { "family": "Mahaffy", "given": "Paul R." }, "orcid": "0000-0003-1896-1726" } ] }, "title": "In Situ Geochronology on Mars and the Development of Future Instrumentation", "ispublished": "pub", "full_text_status": "public", "keywords": "Mars; Mars rovers; Geochronology; Instrument development", "note": "\u00a9 2019 Barbara A. Cohen; Published by Mary Ann Liebert, Inc.\nThis Open Access article is distributed under the terms of the Creative Commons Attribution Noncommercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited. \n\nSubmitted 23 March 2018; Accepted 15 June 2019; Online Ahead of Print: July 30, 2019. \n\nThis work was enabled by the NASA Mars Science Laboratory (MSL) and SAM operations, engineering, and scientific teams. B.A.C. and K.A.F. acknowledge support from the NASA MSL Participating Scientist Program. Data from these experiments are archived in the Planetary Data System (pds.nasa.gov). The authors thank two anonymous reviewers for their insightful reviews that significantly strengthened this article. We used the NASA Astrophysical Data Service (adsabs.harvard.edu). \n\nNo competing financial interests exist.\n\nPublished - ast.2018.1871.pdf
", "abstract": "We review the in situ geochronology experiments conducted by the Mars Science Laboratory mission's Curiosity rover to understand when the Gale Crater rocks formed, underwent alteration, and became exposed to cosmogenic radiation. These experiments determined that the detrital minerals in the sedimentary rocks of Gale are \u223c4 Ga, consistent with their origin in the basalts surrounding the crater. The sedimentary rocks underwent fluid-moderated alteration 2 Gyr later, which may mark the closure of aqueous activity at Gale Crater. Over the past several million years, wind-driven processes have dominated, denuding the surfaces by scarp retreat. The Curiosity measurements validate radiometric dating techniques on Mars and guide the way for future instrumentation to make more precise measurements that will further our understanding of the geological and astrobiological history of the planet.", "date": "2019-11", "date_type": "published", "publication": "Astrobiology", "volume": "19", "number": "11", "publisher": "Mary Ann Liebert", "pagerange": "1303-1314", "id_number": "CaltechAUTHORS:20190805-144122998", "issn": "1531-1074", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190805-144122998", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1089/ast.2018.1871", "primary_object": { "basename": "ast.2018.1871.pdf", "url": "https://authors.library.caltech.edu/records/ctk15-qwn54/files/ast.2018.1871.pdf" }, "resource_type": "article", "pub_year": "2019", "author_list": "Cohen, Barbara A.; Malespin, Charles A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/se21d-xzj71", "eprint_id": 98753, "eprint_status": "archive", "datestamp": "2023-08-22 02:32:09", "lastmod": "2023-10-18 17:37:09", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Schmitz-Birger", "name": { "family": "Schmitz", "given": "Birger" }, "orcid": "0000-0001-9171-5623" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Goderis-S", "name": { "family": "Goderis", "given": "Steven" }, "orcid": "0000-0002-6666-7153" }, { "id": "Heck-P-R", "name": { "family": "Heck", "given": "Philipp R." }, "orcid": "0000-0002-6319-2594" }, { "id": "Bergstr\u00f6m-S-M", "name": { "family": "Bergstr\u00f6m", "given": "Stig M." } }, { "id": "Boschi-S", "name": { "family": "Boschi", "given": "Samuele" } }, { "id": "Claeys-P", "name": { "family": "Claeys", "given": "Philippe" }, "orcid": "0000-0002-4585-7687" }, { "id": "Debaille-V", "name": { "family": "Debaille", "given": "Vinciane" } }, { "id": "Dronov-A", "name": { "family": "Dronov", "given": "Andrei" }, "orcid": "0000-0002-0229-8598" }, { "id": "van-Ginneken-M", "name": { "family": "van Ginneken", "given": "Matthias" }, "orcid": "0000-0002-2508-7021" }, { "id": "Harper-D-A-T", "name": { "family": "Harper", "given": "David A. T." }, "orcid": "0000-0003-1315-9494" }, { "id": "Iqbal-F", "name": { "family": "Iqbal", "given": "Faisal" } }, { "id": "Friberg-J", "name": { "family": "Friberg", "given": "Johan" }, "orcid": "0000-0002-7971-4967" }, { "id": "Liao-Shiyong", "name": { "family": "Liao", "given": "Shiyong" }, "orcid": "0000-0003-4222-059X" }, { "id": "Martin-Ellinor", "name": { "family": "Martin", "given": "Ellinor" }, "orcid": "0000-0001-7109-0240" }, { "id": "Meier-M-M-M", "name": { "family": "Meier", "given": "Matthias M. M." }, "orcid": "0000-0002-7179-4173" }, { "id": "Peucker-Ehrenbrink-B", "name": { "family": "Peucker-Ehrenbrink", "given": "Bernhard" }, "orcid": "0000-0002-3819-992X" }, { "id": "Soens-B", "name": { "family": "Soens", "given": "Bastien" } }, { "id": "Wieler-R", "name": { "family": "Wieler", "given": "Rainer" }, "orcid": "0000-0001-5666-7494" }, { "id": "Terfelt-F", "name": { "family": "Terfelt", "given": "Fredrik" } } ] }, "title": "An extraterrestrial trigger for the mid-Ordovician ice age: Dust from the breakup of the L-chondrite parent body", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY). \n\nSubmitted 21 March 2019. Accepted 19 August 2019. Published 18 September 2019. \n\nWe are grateful to G\u00f6ran, Gustav, S\u00f6ren, and Stig Thor for long-term support with samples from the Thorsberg quarry. K. Deppert, P. Eriksson, and P. Kristiansson made this study possible at Lund University. Three reviewers helped to improve the paper. This is a contribution to the ongoing Ordovician IGCP 653 project. \n\nB.Sc. was supported by the Swedish Research Council, the Knut and Alice Wallenberg Foundation, and an ERC-Advanced grant (ASTROGEOBIOSPHERE 213000). P.R.H. was supported by the Tawani Foundation. M.M.M.M. was supported by an Ambizione grant from the Swiss National Science Foundation. A.D. was supported by the Regional Governmental Program of Competitive Growth of Kazan Federal University and Russian Foundation for Basic Research (grant N19-05-00748). D.A.T.H. was supported by a fellowship from the Leverhulme Trust. S.G., P.C., M.v.G., and B.So. were supported by the Belgian Science Policy (Belspo), the FWO, and the VUB strategic program. V.D. was supported by the FRS-FNRS, Belspo, and the ERC-Starting Grant (ISoSyC 336718). \n\nAuthor contributions: B.Sc. conceived and coordinated the project. K.A.F. performed the He-3 analyses. S.G. led the study of the Antarctic micrometeorites, supported by P.C., V.D., M.v.G., and B.So.. P.R.H. interpreted the 21Ne results and drafted Fig. 3, with help from R.W. and M.M.M.M. B.P.-E. performed the osmium isotope analyses. A.D. contributed to the regional geology and sea level history of the Ordovician. J.F. focused on the effects of extraterrestrial dust in atmospheres. S.M.B. and D.A.T.H. were responsible for the broad area of Ordovician paleontology and stratigraphy. B.Sc., S.B., F.I., S.L., and E.M. recovered and analyzed the spinels and interpreted their origin. F.T. supervised the work in the Astrogeobiology Laboratory. B.Sc. wrote the first draft, and all authors contributed to the interpretation of the results and to the final text. \n\nThe authors declare that they have no competing interests. \n\nData and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Additional data related to this paper may be requested from the authors.\n\nPublished - eaax4184.full.pdf
Supplemental Material - aax4184_Data_file_S1.pdf
Supplemental Material - aax4184_Data_file_S2.xlsx
Supplemental Material - aax4184_Data_file_S3.xlsx
Supplemental Material - aax4184_Data_file_S4.xlsx
Supplemental Material - aax4184_Data_file_S5.pdf
Supplemental Material - aax4184_SM.pdf
", "abstract": "The breakup of the L-chondrite parent body in the asteroid belt 466 million years (Ma) ago still delivers almost a third of all meteorites falling on Earth. Our new extraterrestrial chromite and ^3He data for Ordovician sediments show that the breakup took place just at the onset of a major, eustatic sea level fall previously attributed to an Ordovician ice age. Shortly after the breakup, the flux to Earth of the most fine-grained, extraterrestrial material increased by three to four orders of magnitude. In the present stratosphere, extraterrestrial dust represents 1% of all the dust and has no climatic significance. Extraordinary amounts of dust in the entire inner solar system during >2 Ma following the L-chondrite breakup cooled Earth and triggered Ordovician icehouse conditions, sea level fall, and major faunal turnovers related to the Great Ordovician Biodiversification Event.", "date": "2019-09-18", "date_type": "published", "publication": "Science Advances", "volume": "5", "number": "9", "publisher": "American Association for the Advancement of Science", "pagerange": "Art. No. eaax4184", "id_number": "CaltechAUTHORS:20190919-113942345", "issn": "2375-2548", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190919-113942345", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Swedish Research Council" }, { "agency": "Knut and Alice Wallenberg Foundation" }, { "agency": "European Research Council (ERC)", "grant_number": "213000" }, { "agency": "Tawani Foundation" }, { "agency": "Swiss National Science Foundation (SNSF)" }, { "agency": "Regional Governmental Program of Competitive Growth of Kazan Federal University" }, { "agency": "Russian Foundation for Basic Research", "grant_number": "N19-05-00748" }, { "agency": "Leverhulme Trust" }, { "agency": "Belgian Federal Science Policy Office (BELSPO)" }, { "agency": "Fonds Wetenschappelijk Onderzoek (FWO)" }, { "agency": "Vrije Universiteit Brussel" }, { "agency": "Fonds de la Recherche Scientifique (FNRS)" }, { "agency": "European Research Council (ERC)", "grant_number": "336718" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/sciadv.aax4184", "primary_object": { "basename": "aax4184_Data_file_S3.xlsx", "url": "https://authors.library.caltech.edu/records/se21d-xzj71/files/aax4184_Data_file_S3.xlsx" }, "related_objects": [ { "basename": "aax4184_Data_file_S4.xlsx", "url": "https://authors.library.caltech.edu/records/se21d-xzj71/files/aax4184_Data_file_S4.xlsx" }, { "basename": "aax4184_Data_file_S5.pdf", "url": "https://authors.library.caltech.edu/records/se21d-xzj71/files/aax4184_Data_file_S5.pdf" }, { "basename": "aax4184_SM.pdf", "url": "https://authors.library.caltech.edu/records/se21d-xzj71/files/aax4184_SM.pdf" }, { "basename": "eaax4184.full.pdf", "url": "https://authors.library.caltech.edu/records/se21d-xzj71/files/eaax4184.full.pdf" }, { "basename": "aax4184_Data_file_S1.pdf", "url": "https://authors.library.caltech.edu/records/se21d-xzj71/files/aax4184_Data_file_S1.pdf" }, { "basename": "aax4184_Data_file_S2.xlsx", "url": "https://authors.library.caltech.edu/records/se21d-xzj71/files/aax4184_Data_file_S2.xlsx" } ], "resource_type": "article", "pub_year": "2019", "author_list": "Schmitz, Birger; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/seh2e-vmb46", "eprint_id": 95734, "eprint_status": "archive", "datestamp": "2023-08-22 02:13:08", "lastmod": "2023-10-20 20:30:45", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vasconcelos-P-M", "name": { "family": "Vasconcelos", "given": "Paulo M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Stone-J-O", "name": { "family": "Stone", "given": "John" } }, { "id": "Piacentini-T", "name": { "family": "Piacentini", "given": "Thiago" } }, { "id": "Fifield-L-K", "name": { "family": "Fifield", "given": "L. Keith" } } ] }, "title": "Stranded landscapes in the humid tropics: Earth's oldest land surfaces", "ispublished": "pub", "full_text_status": "public", "keywords": "40Ar/39Ar Mn oxide geochronology; hematite cosmogenic 3He; quartz cosmogenic 10Be and 26Al; calcite cosmogenic 36Cl; cratonal landscape; Neoproterozoic banded iron-formation", "note": "\u00a9 2019 Elsevier B.V.\n\nReceived 13 December 2018, Accepted 9 April 2019, Available online 23 May 2019.\n\nWe thank Arildo Oliveira for facilitating access to the Urucum Mine; the Australian Research Council for partially funding the ^(40)Ar/^(39)Ar laboratory at UQ (ARC Equipment Grant A39531815); and the CNPq PhD scholarship grant GDE200895/2009-5 to T. Piacentini. Kurt Krigbaum and Joy Laydbak assisted with sample preparation in the UW Cosmogenic Nuclide Lab. UW work on this project supported by National Science Foundation award EAR 9805132.\n\nSupplemental Material - 1-s2.0-S0012821X19302171-mmc1_lrg.jpg
Supplemental Material - 1-s2.0-S0012821X19302171-mmc2_lrg.jpg
Supplemental Material - 1-s2.0-S0012821X19302171-mmc3_lrg.jpg
Supplemental Material - 1-s2.0-S0012821X19302171-mmc4_lrg.jpg
Supplemental Material - 1-s2.0-S0012821X19302171-mmc5.xlsx
Supplemental Material - 1-s2.0-S0012821X19302171-mmc6.docx
Supplemental Material - 1-s2.0-S0012821X19302171-mmc7.pdf
", "abstract": "Defying common expectations, some of the oldest landscapes on Earth are found in the humid tropics. ^(40)Ar/^(39)Ar dating shows that Fe-rich regolith that armors the \u223c700\u20131000 m elevation banded iron-formation plateaus at Urucum, Mato Grosso do Sul, Brazil, results from chemical weathering that began at least 70 million years ago. Cosmogenic ^3He concentrations in residual hematite clasts and the underlying saprolite on one plateau imply an extraordinarily slow surface lowering rate of 0.07\u20130.10 m Ma^(\u22121) maintained over the last \u223c17\u201370 Ma. Cosmogenic ^(10)Be and ^(26)Al concentrations in a quartz vein in the same plateau suggest a similarly low surface erosion rate of \u223c0.11\u20130.18 m Ma\u22121 over the past few million years. Cosmogenic ^3He concentrations in goethite cementing a \u223c200 m elevation indurated pediment \u223c3 km northwest of the plateau escarpment yields a minimum exposure age of \u223c2.6 Ma, revealing that some of the low-lying areas had already been incised and locally stabilized by goethite cementation by then. In contrast, ^(36)Cl measurements on limestone outcrops at \u223c170 m elevation and \u223c6.5 km northwest of the Urucum plateau reveal short-term erosion rates of 7.1 \u00b1 0.4 and 10.1 \u00b1 0.5 m Ma^(\u22121), showing that areas not stabilized by goethite cementation are undergoing erosion at a relatively fast pace. The \u223c700 m of relief at Urucum is consistent with differential denudation over \u223c70 Ma controlled by lithological differences in chemical and physical rates of weathering and erosion. Effective chemical weathering and protracted low rates of erosion for the high-elevation surface result in armoring by a resilient residue of hematite blocks that are relatively insoluble and too heavy to transport. Armoring by the surface lag of large chemically resilient hematite blocks and bedded hematite saprolite focuses meteoric water flow into the subsurface and along faults. Preferential subsurface flow along the permeable pathways between insoluble hematite blocks, combined with segmentation of the Urucum Surface into isolated catchments too small to host active drainage systems, brings physical erosion to a stand-still. The only effective erosive processes on the Urucum plateau are subsurface chemical erosion and scarp retreat. Non-steady-state landscapes in which elevation differences result from prolonged differential denudation are a common feature of Earth's southern hemisphere cratons, and they inherit their present form from underlying lithologies coupled with geomorphic processes active since the Mesozoic.", "date": "2019-08-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "519", "publisher": "Elsevier", "pagerange": "152-164", "id_number": "CaltechAUTHORS:20190523-103853641", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190523-103853641", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Australian Research Council", "grant_number": "A39531815" }, { "agency": "Conselho Nacional de Desenvolvimento Cient\u00edfico e Tecnol\u00f3gico (CNPq)", "grant_number": "GDE200895/2009-5" }, { "agency": "NSF", "grant_number": "EAR-9805132" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2019.04.014", "primary_object": { "basename": "1-s2.0-S0012821X19302171-mmc7.pdf", "url": "https://authors.library.caltech.edu/records/seh2e-vmb46/files/1-s2.0-S0012821X19302171-mmc7.pdf" }, "related_objects": [ { "basename": "1-s2.0-S0012821X19302171-mmc1_lrg.jpg", "url": "https://authors.library.caltech.edu/records/seh2e-vmb46/files/1-s2.0-S0012821X19302171-mmc1_lrg.jpg" }, { "basename": "1-s2.0-S0012821X19302171-mmc2_lrg.jpg", "url": "https://authors.library.caltech.edu/records/seh2e-vmb46/files/1-s2.0-S0012821X19302171-mmc2_lrg.jpg" }, { "basename": "1-s2.0-S0012821X19302171-mmc3_lrg.jpg", "url": "https://authors.library.caltech.edu/records/seh2e-vmb46/files/1-s2.0-S0012821X19302171-mmc3_lrg.jpg" }, { "basename": "1-s2.0-S0012821X19302171-mmc4_lrg.jpg", "url": "https://authors.library.caltech.edu/records/seh2e-vmb46/files/1-s2.0-S0012821X19302171-mmc4_lrg.jpg" }, { "basename": "1-s2.0-S0012821X19302171-mmc5.xlsx", "url": "https://authors.library.caltech.edu/records/seh2e-vmb46/files/1-s2.0-S0012821X19302171-mmc5.xlsx" }, { "basename": "1-s2.0-S0012821X19302171-mmc6.docx", "url": "https://authors.library.caltech.edu/records/seh2e-vmb46/files/1-s2.0-S0012821X19302171-mmc6.docx" } ], "resource_type": "article", "pub_year": "2019", "author_list": "Vasconcelos, Paulo M.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3yezp-q7r67", "eprint_id": 100747, "eprint_status": "archive", "datestamp": "2023-08-22 02:11:15", "lastmod": "2023-10-18 21:49:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shaw-J-M", "name": { "family": "Shaw", "given": "J. M." } }, { "id": "Cooper-F-J", "name": { "family": "Cooper", "given": "F. J." } }, { "id": "Boyce-A-J", "name": { "family": "Boyce", "given": "A. J." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Evenstar-L", "name": { "family": "Evenstar", "given": "L." } } ] }, "title": "Using weathering and alteration minerals to constrain water table movement and supergene enrichment of porphyry copper deposits in the Central Andes", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 Society for Geology Applied to Mineral Deposits (SGA).\n\nFunding: NERC DTP studentship; NERC Natural Environment Research Council.", "abstract": "The Atacama Desert of northern Chile hosts many of the world's largest porphyry copper deposits (PCDs), many of which have been upgraded through supergene enrichment (Sillitoe and McKee 1996). Enrichment of exhumed PCDs occurs in the near-surface weathering environment, when copper is leached from primary sulphides and reprecipitated beneath the water table to form a concentrated blanket of secondary copper minerals (e.g. chalcocite).\n\nThe Atacama is one of the driest regions on Earth, but supergene enrichment requires precipitation to drive the aqueous redistribution of metals. Previous alunite dating studies have suggested enrichment stopped in the middle Miocene, due to an increase in aridity. This conclusion is supported by the youngest supergene alunite ages from several PCDs clustering around 14 Ma (Sillitoe 2005). Hematite also forms in the leached caps of PCDs and hematite (U-Th)/He geochronology provides a tool to track the downward progression of weathering fronts (e.g. Cooper et al. 2016).\n\nThis study will combine Ar-40/Ar-39 dating of supergene alunite (a proxy for the timing of copper enrichment) with hematite geochronology (as an indicator of the progression of weathering) to better understand the link between water table movement and supergene enrichment of Central Andean PCDs.", "date": "2019-08", "date_type": "published", "publisher": "Society for Geology Applied to Mineral Deposits (SGA)", "id_number": "CaltechAUTHORS:20200116-080142643", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200116-080142643", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Natural Environment Research Council (NERC)" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "resource_type": "book_section", "pub_year": "2019", "author_list": "Shaw, J. M.; Cooper, F. J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/tm1qq-pnm87", "eprint_id": 94271, "eprint_status": "archive", "datestamp": "2023-09-29 01:35:03", "lastmod": "2023-10-24 15:27:05", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kohn-B-P", "name": { "family": "Kohn", "given": "Barry" } }, { "id": "Weissbrod-T", "name": { "family": "Weissbrod", "given": "Tuvia" } }, { "id": "Chung-Ling-Ho", "name": { "family": "Chung", "given": "Ling" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Ken" }, "orcid": "0000-0002-7846-7546" }, { "id": "Bodorkos-S", "name": { "family": "Bodorkos", "given": "Simon" } } ] }, "title": "Low-temperature thermochronology of francolite: Insights into timing of Dead Sea Transform motion", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2018 Wiley. \n\nAccepted manuscript online: 04 March 2019.\n\nSupplemental Material - ter12387-sup-0001-figs1.pdf
Supplemental Material - ter12387-sup-0002-tables1.xlsx
Supplemental Material - ter12387-sup-0003-tables2.pdf
Supplemental Material - ter12387-sup-0004-tables3.xlsx
", "abstract": "Cambrian siliciclastic sequences along the Dead Sea Transform (DST) margin in southern Israel and southern Jordan host both detrital fluorapatite [D\u2010apatite] and U\u2010rich authigenic carbonate\u2010fluorapatite (francolite) [A\u2010apatite]. D\u2010apatite and underlying Neoproterozoic basement apatite yield fission track (FT) data reflecting Paleozoic\u2010Mesozoic sedimentary cycles and epeirogenic events, and dispersed (U\u2010Th\u2010Sm)/He (AHe) ages. A\u2010apatite, which may partially or completely replace D\u2010apatite, yields an early Miocene FT age suggesting formation by fracturing, hydrothermal fluid ascent and intra\u2010strata recrystallisation, linked to early DST motion. The DST, separating the African and Arabian plates, records ~105 km of sinistral strike\u2010slip displacement, but became more transtensional post\u20105 Ma. Helium diffusion measurements on A\u2010apatite are consistent with thermally activated volume diffusion, indicating Tc ~52\u201056\u00b110\u00b0C (cooling rate 10\u00b0C/Myr). A\u2010apatite AHe data record Pliocene cooling (~35\u201040\u00b0C) during the transtensional phase of movement. This suggests that timing of important milestones in DST motion can be discerned using A\u2010apatite low\u2010temperature thermochronology data alone.", "date": "2019-06", "date_type": "published", "publication": "Terra Nova", "volume": "31", "number": "3", "publisher": "Blackwell Publishing", "pagerange": "205-219", "id_number": "CaltechAUTHORS:20190328-180954041", "issn": "0954-4879", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190328-180954041", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/ter.12387", "primary_object": { "basename": "ter12387-sup-0001-figs1.pdf", "url": "https://authors.library.caltech.edu/records/tm1qq-pnm87/files/ter12387-sup-0001-figs1.pdf" }, "related_objects": [ { "basename": "ter12387-sup-0002-tables1.xlsx", "url": "https://authors.library.caltech.edu/records/tm1qq-pnm87/files/ter12387-sup-0002-tables1.xlsx" }, { "basename": "ter12387-sup-0003-tables2.pdf", "url": "https://authors.library.caltech.edu/records/tm1qq-pnm87/files/ter12387-sup-0003-tables2.pdf" }, { "basename": "ter12387-sup-0004-tables3.xlsx", "url": "https://authors.library.caltech.edu/records/tm1qq-pnm87/files/ter12387-sup-0004-tables3.xlsx" } ], "resource_type": "article", "pub_year": "2019", "author_list": "Kohn, Barry; Weissbrod, Tuvia; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ajnwv-pmt81", "eprint_id": 92712, "eprint_status": "archive", "datestamp": "2023-08-22 01:17:58", "lastmod": "2023-10-20 16:21:03", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gothmann-A-M", "name": { "family": "Gothmann", "given": "Anne M." } }, { "id": "Higgins-J-A", "name": { "family": "Higgins", "given": "John A." } }, { "id": "Adkins-J-F", "name": { "family": "Adkins", "given": "Jess F." }, "orcid": "0000-0002-3174-5190" }, { "id": "Broecker-W-S", "name": { "family": "Broecker", "given": "Wally S." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "McKeon-R-E", "name": { "family": "McKeon", "given": "Ryan" } }, { "id": "Stolarski-J", "name": { "family": "Stolarski", "given": "Jaros\u0142aw" } }, { "id": "Planavsky-N-J", "name": { "family": "Planavsky", "given": "Noah" } }, { "id": "Wang-Xiangli", "name": { "family": "Wang", "given": "Xiangli" } }, { "id": "Bender-M-L", "name": { "family": "Bender", "given": "Michael L." } } ] }, "title": "A Cenozoic Record of Seawater Uranium in Fossil Corals", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2019 Published by Elsevier Ltd. \n\nReceived 9 August 2018, Accepted 30 January 2019, Available online 6 February 2019. \n\nWe would like to thank Francois L.H. Tissot for helpful comments on multiple drafts of this manuscript as well as Associate Editor, Claudine Stirling, and an anonymous reviewer. We thank Stephen Cairns and Tim Coffer (Smithsonian Institution), Linda Ivany (Syracuse University), Roger Portell (Florida Museum of Natural History), Anne Cohen and Bill Thompson (WHOI), the USGS, and Gregory Dietl (Paleontological Research Institution) for loaning samples. Elizabeth Lundstrom (Princeton University) and Lindsey Hedges (California Institute of Technology) provided critical analytical support. We also thank Sarah Jane White (USGS), Francois Morel (Princeton University) and Will Amidon (Middlebury College) for helpful discussions that improved this manuscript.", "abstract": "We measured U/Ca ratios, ^4He concentrations, ^(234)U/^(238)U, and ^(238)U/^(235)U in a subset of well-preserved aragonitic scleractinian fossil corals previously described by Gothmann et al. (2015). Comparisons of measured fossil coral He/U ages with the stratigraphic age demonstrate that well-preserved coral aragonite retains most or all of its radiogenic He for 10's of millions of years. Such samples must be largely or entirely free of alteration, including neomorphism. Measurements of ^(234)U/^(238)U and ^(238)U/^(235)U further help to characterize the fidelity with which the original U concentration has been preserved. Analyses of fossil coral U/Ca show that the seawater U/Ca ratio rose by a factor of 4-5 between the Early Cenozoic and today. Possible explanations for the observed increase include (1) the stabilization of U in seawater due to an increase in seawater [CO_3^(2-)], and a resulting increase in UO_2-CO_3 complexation as originally suggested by Broecker (1971); (2) a decrease in the rate of low-temperature hydrothermal alteration from Early Cenozoic to present, leading to a diminished U sink and higher seawater [U]; or (3) a decrease in uranium removal in reducing sediments, again leading to higher seawater [U].", "date": "2019-04-01", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "250", "publisher": "Elsevier", "pagerange": "173-190", "id_number": "CaltechAUTHORS:20190206-103754732", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190206-103754732", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2019.01.039", "resource_type": "article", "pub_year": "2019", "author_list": "Gothmann, Anne M.; Higgins, John A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/a513z-05g61", "eprint_id": 92406, "eprint_status": "archive", "datestamp": "2023-08-22 01:09:35", "lastmod": "2023-10-20 15:39:51", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lund-David-C", "name": { "family": "Lund", "given": "David C." }, "orcid": "0000-0002-4847-2889" }, { "id": "Pavia-Frank-J", "name": { "family": "Pavia", "given": "Frank J." }, "orcid": "0000-0003-3627-0179" }, { "id": "Seeley-Emily-I", "name": { "family": "Seeley", "given": "Emily I." } }, { "id": "McCart-Sarah-E", "name": { "family": "McCart", "given": "Sarah E." } }, { "id": "Rafter-Patrick-A", "name": { "family": "Rafter", "given": "Patrick A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Asimow-P-D", "name": { "family": "Asimow", "given": "Paul D." }, "orcid": "0000-0001-6025-8925" }, { "id": "Anderson-Robert-F", "name": { "family": "Anderson", "given": "Robert F." }, "orcid": "0000-0002-8472-2494" } ] }, "title": "Hydrothermal scavenging of \u00b2\u00b3\u2070Th on the Southern East Pacific Rise during the last deglaciation", "ispublished": "pub", "full_text_status": "public", "keywords": "230-Thorium; hydrothermal scavenging; glacial\u2013interglacial; East Pacific Rise; 231-Protactinium", "note": "\u00a9 2019 Elsevier B.V. \n\nReceived 28 August 2018, Revised 23 December 2018, Accepted 28 December 2018, Available online 18 January 2019. \n\nDCL, EIS, and SM were supported by NSF award OCE-1558641 and the UCONN Research Excellence Program. We are grateful to David Cady at UCONN for assistance with ICP-MS analyses, Jean Lynch-Stieglitz at Georgia Tech for assistance with stable isotope analyses, and Martin Fleisher at LDEO for assistance with ^(230)Th and \u00b2\u00b3\u00b9Pa analyses. We are also indebted to the Oregon State University Core Repository for the curation of core OC73-3-20. The OSU Repository is supported by NSF award OCE-1558679. PDA was supported by NSF awards OCE-1558372 and EAR-1551433. FJP was supported by an NSF-GRFP(DGE-16-44869). All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials.\n\nSupplemental Material - 1-s2.0-S0012821X1930007X-mmc1.docx
Supplemental Material - 1-s2.0-S0012821X1930007X-mmc10.pdf
Supplemental Material - 1-s2.0-S0012821X1930007X-mmc2.pdf
Supplemental Material - 1-s2.0-S0012821X1930007X-mmc3.pdf
Supplemental Material - 1-s2.0-S0012821X1930007X-mmc4.pdf
Supplemental Material - 1-s2.0-S0012821X1930007X-mmc5.pdf
Supplemental Material - 1-s2.0-S0012821X1930007X-mmc6.pdf
Supplemental Material - 1-s2.0-S0012821X1930007X-mmc7.pdf
Supplemental Material - 1-s2.0-S0012821X1930007X-mmc8.pdf
Supplemental Material - 1-s2.0-S0012821X1930007X-mmc9.pdf
", "abstract": "Thorium-230 (\u00b2\u00b3\u2070Th) is a fundamental tool for estimating sediment fluxes in the open ocean. Because \u00b2\u00b3\u2070Th is rapidly scavenged by particles falling through the water column, the flux of \u00b2\u00b3\u2070Th to underlying sediments is typically equal to its water column production rate. However, recent surveys suggest hydrothermal plumes are unusually efficient scavengers of \u00b2\u00b3\u2070Th. Here we show that hydrothermal scavenging on the Southern East Pacific Rise (SEPR) resulted in \u00b2\u00b3\u2070Th fluxes several times higher than the water column production rate during the last deglaciation. Elevated fluxes likely require diffusive transport of dissolved \u00b2\u00b3\u2070Th from the ridge flanks towards the ridge crest. Depending on the length-scale of \u00b2\u00b3\u2070Th transport, the resulting deficits in \u00b2\u00b3\u2070Th may yield overestimates of sediment flux to ridge flank sediments. We also show that Fe fluxes at 19\u00b0S on the SEPR lag those at 11\u00b0S and 6\u00b0S by several thousand years, inconsistent with a signal driven by changes in deep water pH and oxygen levels. Instead, variable hydrothermal activity is the simplest explanation of the observed signals in the Pacific, Indian, and Atlantic basins.", "date": "2019-03-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "510", "publisher": "Elsevier", "pagerange": "64-72", "id_number": "CaltechAUTHORS:20190123-072432500", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190123-072432500", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OCE-1558641" }, { "agency": "University of Connecticut" }, { "agency": "NSF", "grant_number": "OCE-1558679" }, { "agency": "NSF", "grant_number": "OCE-1558372" }, { "agency": "NSF", "grant_number": "EAR-1551433" }, { "agency": "NSF Graduate Research Fellowship", "grant_number": "DGE-16-44869" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2018.12.037", "primary_object": { "basename": "1-s2.0-S0012821X1930007X-mmc10.pdf", "url": "https://authors.library.caltech.edu/records/a513z-05g61/files/1-s2.0-S0012821X1930007X-mmc10.pdf" }, "related_objects": [ { "basename": "1-s2.0-S0012821X1930007X-mmc7.pdf", "url": "https://authors.library.caltech.edu/records/a513z-05g61/files/1-s2.0-S0012821X1930007X-mmc7.pdf" }, { "basename": "1-s2.0-S0012821X1930007X-mmc8.pdf", "url": "https://authors.library.caltech.edu/records/a513z-05g61/files/1-s2.0-S0012821X1930007X-mmc8.pdf" }, { "basename": "1-s2.0-S0012821X1930007X-mmc1.docx", "url": "https://authors.library.caltech.edu/records/a513z-05g61/files/1-s2.0-S0012821X1930007X-mmc1.docx" }, { "basename": "1-s2.0-S0012821X1930007X-mmc2.pdf", "url": "https://authors.library.caltech.edu/records/a513z-05g61/files/1-s2.0-S0012821X1930007X-mmc2.pdf" }, { "basename": "1-s2.0-S0012821X1930007X-mmc3.pdf", "url": "https://authors.library.caltech.edu/records/a513z-05g61/files/1-s2.0-S0012821X1930007X-mmc3.pdf" }, { "basename": "1-s2.0-S0012821X1930007X-mmc4.pdf", "url": "https://authors.library.caltech.edu/records/a513z-05g61/files/1-s2.0-S0012821X1930007X-mmc4.pdf" }, { "basename": "1-s2.0-S0012821X1930007X-mmc5.pdf", "url": "https://authors.library.caltech.edu/records/a513z-05g61/files/1-s2.0-S0012821X1930007X-mmc5.pdf" }, { "basename": "1-s2.0-S0012821X1930007X-mmc6.pdf", "url": "https://authors.library.caltech.edu/records/a513z-05g61/files/1-s2.0-S0012821X1930007X-mmc6.pdf" }, { "basename": "1-s2.0-S0012821X1930007X-mmc9.pdf", "url": "https://authors.library.caltech.edu/records/a513z-05g61/files/1-s2.0-S0012821X1930007X-mmc9.pdf" } ], "resource_type": "article", "pub_year": "2019", "author_list": "Lund, David C.; Pavia, Frank J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/m5d35-0a373", "eprint_id": 90456, "eprint_status": "archive", "datestamp": "2023-08-22 00:38:27", "lastmod": "2023-10-18 23:27:50", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Horton-Forrest", "name": { "family": "Horton", "given": "Forrest" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Jackson-Matthew-G", "name": { "family": "Jackson", "given": "Matthew" } } ] }, "title": "Helium distributions in ocean island basalt olivines revealed by X-ray computed tomography and single-grain crushing experiments", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2018 Elsevier. \n\nReceived 30 April 2018, Revised 1 October 2018, Accepted 12 October 2018, Available online 28 October 2018. \n\nThis research was supported by NSF award number 1650308. We thank the members of the X-ray CT Facility at University of Texas Austin; William Carlson and Jessica Maisano, in particular, provided crucial assistance and advice. A thorough review by Jonathan Tucker improved this manuscript, as did two anonymous reviews.\n\nSupplemental Material - 1-s2.0-S0016703718305994-mmc1.pdf
Supplemental Material - 1-s2.0-S0016703718305994-mmc2.pdf
", "abstract": "X-ray computed tomography of individual olivine crystals in basalts from Ofu and Olosega islands, American Samoa, reveals that a small fraction of the olivines contain the vast majority of the fluid inclusions. Single-grain crushing experiments demonstrate that He and CO_2 reside primarily in these inclusions. Low CO_2 pressures in most grains, corresponding to depths of less than 1\u202fkm, provide evidence of ubiquitous decrepitation and associated pressure reduction in the fluid inclusions. Even so, the olivines with the highest inclusion volumes yielded sufficient He to obtain precise He concentrations and isotopic compositions. Within analytical uncertainty, ^3He/^4He ratios are homogeneous among the olivines from each basalt, but among basalts, the ratios range from 21 to 35 Ra. The total range in C/^3He ratio within the analyzed olivines is from 3.6\u202f\u00d7\u202f10^7 to 1.5\u202f\u00d7\u202f10^(10), and varies by nearly an order of magnitude within the olivines from each basalt. We postulate that this wide range of C/^3He ratios is caused by grain-scale decoupling of C and ^3He due to extensive He diffusion out of fluid inclusions through the olivine lattice during magma ascent and cooling. If so, primary Ofu-Olosega magmas probably had C/^3He ratios less than 4\u202f\u00d7\u202f10^8, which is lower than previous estimates for hotspot magmas.", "date": "2019-01-01", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "244", "publisher": "Elsevier", "pagerange": "467-477", "id_number": "CaltechAUTHORS:20181029-094838605", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181029-094838605", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1650308" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2018.10.013", "primary_object": { "basename": "1-s2.0-S0016703718305994-mmc1.pdf", "url": "https://authors.library.caltech.edu/records/m5d35-0a373/files/1-s2.0-S0016703718305994-mmc1.pdf" }, "related_objects": [ { "basename": "1-s2.0-S0016703718305994-mmc2.pdf", "url": "https://authors.library.caltech.edu/records/m5d35-0a373/files/1-s2.0-S0016703718305994-mmc2.pdf" } ], "resource_type": "article", "pub_year": "2019", "author_list": "Horton, Forrest; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/nw3hc-wbm02", "eprint_id": 90557, "eprint_status": "archive", "datestamp": "2023-08-22 00:39:02", "lastmod": "2023-10-19 14:34:17", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Avice-Guillaum", "name": { "family": "Avice", "given": "G." }, "orcid": "0000-0003-0962-0049" }, { "id": "Belousov-A", "name": { "family": "Belousov", "given": "A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Madzunkov-S-M", "name": { "family": "Madzunkov", "given": "S. M." } }, { "id": "Simcic-Jurij", "name": { "family": "Simcic", "given": "J." }, "orcid": "0000-0001-9806-8123" }, { "id": "Nikoli\u0107-D", "name": { "family": "Nikoli\u0107", "given": "D." } }, { "id": "Darrach-M-R", "name": { "family": "Darrach", "given": "M. R." } }, { "id": "Sotin-Christophe", "name": { "family": "Sotin", "given": "C." }, "orcid": "0000-0003-3947-1072" } ] }, "title": "High-precision measurements of krypton and xenon isotopes with a new static-mode quadrupole ion trap mass spectrometer", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2018 The Royal Society of Chemistry. \n\nThe article was received on 27 Jun 2018, accepted on 23 Oct 2018 and first published on 23 Oct 2018. \n\nLaurent R\u00e9musat is acknowledged for his advices for acquiring Allende samples originally prepared by S. Epstein and Mark B. Garcia for his handling of the GPS collection at Caltech. Jonathan Treffkorn is thanked for help during the preparation of the experiments conducted at Caltech. We thank Dr Smith for her editorial handling of the manuscript and two reviewers for helpful comments. This work has been performed at the California Institute of Technology and at the Jet Propulsion Laboratory (JPL), California Institute of Technology (Caltech), under contract to NASA. \n\nThere are no conflicts to declare.\n\nAccepted Version - 2012.07062.pdf
", "abstract": "Measuring the abundance and isotopic composition of noble gases in planetary atmospheres can answer fundamental questions in cosmochemistry and comparative planetology. However, noble gases are rare elements, a feature making their measurement challenging even on Earth. Furthermore, in space applications, power consumption, volume and mass constraints on spacecraft instrument accommodations require the development of compact innovative instruments able to meet the engineering requirements of the mission while still meeting the science requirements. Here we demonstrate the ability of the quadrupole ion trap mass spectrometer (QITMS) developed at the Jet Propulsion Laboratory (Caltech, Pasadena) to measure low quantities of heavy noble gases (Kr, Xe) in static operating mode and in the absence of a buffer gas such as helium. The sensitivity reaches 10^(13) cps Torr^(\u22121) (about 10^(11) cps Pa^(\u22121)) of gas (Kr or Xe). The instrument is able to measure gas in static mode for extended periods of time (up to 48 h) enabling the acquisition of thousands of isotope ratios per measurement. Errors on isotope ratios follow predictions of the counting statistics and the instrument provides reproducible results over several days of measurements. For example, 1.7 \u00d7 10^(\u221210) Torr (2.3 \u00d7 10^(\u22128) Pa) of Kr measured continuously for 7 hours yielded a 0.6\u2030 precision on the ^(86)Kr/^(84)Kr ratio. Measurements of terrestrial and extraterrestrial samples reproduce values from the literature. A compact instrument based upon the QITMS design would have a sensitivity high enough to reach the precision on isotope ratios (e.g. better than 1% for ^(129,131\u2013136)Xe/^(130)Xe ratios) necessary for a scientific payload measuring noble gases collected in the Venus atmosphere.", "date": "2019-01-01", "date_type": "published", "publication": "Journal of Analytical Atomic Spectrometry", "volume": "34", "number": "1", "publisher": "Royal Society of Chemistry", "pagerange": "104-117", "id_number": "CaltechAUTHORS:20181101-101938362", "issn": "0267-9477", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181101-101938362", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1039/c8ja00218e", "primary_object": { "basename": "2012.07062.pdf", "url": "https://authors.library.caltech.edu/records/nw3hc-wbm02/files/2012.07062.pdf" }, "resource_type": "article", "pub_year": "2019", "author_list": "Avice, G.; Belousov, A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/z4tzn-jgg61", "eprint_id": 87552, "eprint_status": "archive", "datestamp": "2023-08-24 00:00:48", "lastmod": "2023-10-18 21:16:02", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Grant-J-A", "name": { "family": "Grant", "given": "John A." }, "orcid": "0000-0001-8276-1281" }, { "id": "Golombek-M-P", "name": { "family": "Golombek", "given": "Matthew P." }, "orcid": "0000-0002-1928-2293" }, { "id": "Wilson-S-A", "name": { "family": "Wilson", "given": "Sharon A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Williford-K-H", "name": { "family": "Williford", "given": "Ken H." }, "orcid": "0000-0003-0633-408X" }, { "id": "Chen-Al", "name": { "family": "Chen", "given": "Al" } } ] }, "title": "The science process for selecting the landing site for the 2020 Mars rover", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2018 Published by Elsevier Ltd. \n\nReceived 13 March 2018, Revised 8 June 2018, Accepted 1 July 2018, Available online 4 July 2018. \n\nThis work was supported by NASA and JPL under JPL subcontract 1442524 to John Grant. Part of the work in this paper was supported by the Mars Program Office and Mars 2020 Project at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The authors thank Tim Goudge and an anonymous reviewer for comments that improved the manuscript.\n\nSupplemental Material - 1-s2.0-S0032063318301077-mmc1.xml
", "abstract": "The process of identifying the landing site for NASA's Mars 2020 rover began in 2013 by defining threshold mission science criteria related to seeking signs of ancient habitable conditions, searching for biosignatures of past microbial life, assembling a returnable cache of samples for possible future return to Earth, and collecting data for planning eventual human missions to the surface of Mars. Mission engineering constraints on elevation and latitude were used to identify candidate landing sites that addressed the scientific objectives of the mission. However, for the first time these constraints did not have a major influence on the viability of candidate sites and, with the new entry, descent, and landing capabilities included in the baseline mission, the vast majority of sites were evaluated and down-selected on the basis of science merit. More than 30 candidate sites with likely acceptable surface and atmospheric conditions were considered at a series of open workshops in the years leading up to the launch. During that period, iteration between engineering constraints and the evolving relative science potential of candidate sites led to the identification of three final candidate sites: Jezero crater (18.4386\u00b0N, 77.5031\u00b0E), northeast (NE) Syrtis (17.8899\u00b0N,77.1599\u00b0E) and Columbia Hills (14.5478\u00b0S, 175.6255\u00b0E). The final landing site will be selected by NASA's Associate Administrator for the Science Mission Directorate. This paper serves as a record of landing site selection activities related primarily to science, an inventory of the number and variety of sites proposed, and a summary of the science potential of the highest-ranking sites.", "date": "2018-12-01", "date_type": "published", "publication": "Planetary and Space Science", "volume": "164", "publisher": "Elsevier", "pagerange": "106-126", "id_number": "CaltechAUTHORS:20180705-130651955", "issn": "0032-0633", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180705-130651955", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "JPL", "grant_number": "1442524" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.pss.2018.07.001", "primary_object": { "basename": "1-s2.0-S0032063318301077-mmc1.xml", "url": "https://authors.library.caltech.edu/records/z4tzn-jgg61/files/1-s2.0-S0032063318301077-mmc1.xml" }, "resource_type": "article", "pub_year": "2018", "author_list": "Grant, John A.; Golombek, Matthew P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/fp0cd-q3319", "eprint_id": 85816, "eprint_status": "archive", "datestamp": "2023-08-22 01:59:32", "lastmod": "2023-10-18 18:49:57", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Helium diffusion parameters of hematite from a single-diffusion-domain crystal", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2018 Elsevier Ltd. \n\nReceived 17 December 2017, Accepted 5 April 2018, Available online 12 April 2018. \n\nThis work was supported by the National Science Foundation, Grant EAR-1144500. Fruitful discussions with Paulo Vasconcelos and helpful reviews by Alexis Ault, Oscar Lovera, and Marissa Tremblay are gratefully acknowledged.", "abstract": "This contribution reports new parameters for helium diffusion in hematite useful for interpretation of cosmogenic ^3He and radiogenic ^4He chronometry. Fragments of a coarse, euhedral single crystal of hematite from Minas Gerais, Brazil were subjected to bulk step-heating helium diffusion experiments after proton irradiation to make a uniform distribution of ^3He. Aliquots of three different grain sizes ranging from \u223c300 to \u223c700 \u03bcm in equivalent-sphere radius yielded helium diffusion activation energies E_a\u223c170 kJ/mol, very similar to previous estimates for E_a in hematite. Uniquely in this specimen, diffusivity varies with the dimensions of the analyzed fragments in precisely the fashion expected if the diffusion domain corresponds to the physical grain. This contrasts with previous studies that concluded that the analyzed hematites consist of polycrystalline aggregates in which helium migration is governed by the size distribution of the constituent crystallites. These new data permit a direct estimate of the helium diffusivity at infinite temperature for hematite of ln(D_o) = -0.66 \u00b1 0.35 cm^2/sec.\nThe major implication of the new diffusion parameters is that hematite is very retentive of helium even at very small crystal sizes. For example, a 20 nm radius hematite crystal, at the smallest end of the size range so far described in dated polycrystalline hematite specimens, will retain more than 99% of its ingrown He over 1 Myr at 30\u00b0C, and more than 90% over 100 Myr. Under most conditions, hematite is close to quantitatively helium-retentive on the Earth's surface, simplifying radiogenic and cosmogenic helium dating of this phase. In a system cooling at 10\u00b0C/Myr, the 20 nm hematite crystal has a He closure temperature of \u223c70\u00b0C, similar to a typical \u223c100 \u03bcm apatite crystal.\nHelium is likely held tightly in hematite owing to its dense hexagonal closest packing structure and absence of migration-enhancing channels. The isostructural minerals corundum and sapphire are likely to be similarly helium retentive.", "date": "2018-06-15", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "231", "publisher": "Elsevier", "pagerange": "117-129", "id_number": "CaltechAUTHORS:20180413-090932832", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180413-090932832", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1144500" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2018.04.005", "resource_type": "article", "pub_year": "2018", "author_list": "Farley, K. A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/yxt5c-gpr72", "eprint_id": 85416, "eprint_status": "archive", "datestamp": "2023-08-22 01:59:23", "lastmod": "2023-10-18 18:12:29", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lowery-Christopher-M", "name": { "family": "Lowery", "given": "Christopher M." }, "orcid": "0000-0002-0101-4397" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Rapid recovery of life at ground zero of the end-Cretaceous mass extinction", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2018 Macmillan Publishers Limited, part of Springer Nature. \n\nReceived: 27 October 2017; Accepted: 3 April 2018; Published online 30 May 2018. \n\nThis research used samples and data provided by the International Ocean Discovery Program (IODP). IODP Expedition 364 was jointly funded by the European Consortium for Ocean Research Drilling (ECORD) and International Continental Drilling Program (ICDP), with contributions and logistical support from the Yucat\u00e1n State Government and Universidad Nacional Aut\u00f3noma de M\u00e9xico (UNAM). We thank T. Cayton for assistance with crushing and washing samples; S. Dameron, R. Moura de Mello and M. Leckie for helpful discussions on benthic foraminifer taxonomy; J. Maner for assistance with the UT ESEM laboratory and R. Martindale for assistance with petrographic microscope imaging. We are particularly grateful for assistance of the staff of the IODP Core Repository in Bremen, Germany for their assistance taking these samples and running shipboard analyses. The authors acknowledge Post-Expedition Awards from the US Science Support Program for C.M.L. and T.J.B., NSF OCE 1737351, and NASA NNX16AJ60G. Funding for F.J.R.-T. was provided by Project CGL2015-66835-P (Secretar\u00eda de Estado de I+D+I, Spain), and Scientific Excellence Unit UCE-2016-05 (Universidad de Granada). \n\nAuthor Contributions: All authors participated in sampling and data collection offshore and/or onshore during IODP\u2013ICDP Expedition 364. C.M.L., T.J.B., F.J.R.-T., H.J. and J.S. collected and analysed microfossil data, M.T.W. provided detailed sedimentology, and J.D.O., P.C. and K.F. collected trace element, X-ray fluorescence and He isotope data, respectively. All authors contributed to writing and/or editing of the manuscript. \n\nThe authors declare no competing interests. \n\nReporting summary: Further information on experimental design is available in the Nature Research Reporting Summary linked to this paper. \n\nData availability: X-ray fluorescence data have previously been published39 and are available online (https://doi.org/10.14379/iodp.proc.364.2017). All other data supporting the findings of this study are available within the paper and its Supplementary Information. \n\nNature thanks B. Huber and the other anonymous reviewer(s) for their contribution to the peer review of this work.\n\nAccepted Version - nihms956943.pdf
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", "abstract": "The Cretaceous/Palaeogene mass extinction eradicated 76% of species on Earth. It was caused by the impact of an asteroid on the Yucat\u00e1n carbonate platform in the southern Gulf of Mexico 66 million years ago, forming the Chicxulub impact crater. After the mass extinction, the recovery of the global marine ecosystem\u2014measured as primary productivity\u2014was geographically heterogeneous; export production in the Gulf of Mexico and North Atlantic\u2013western Tethys was slower than in most other regions taking 300 thousand years (kyr) to return to levels similar to those of the Late Cretaceous period. Delayed recovery of marine productivity closer to the crater implies an impact-related environmental control, such as toxic metal poisoning, on recovery times. If no such geographic pattern exists, the best explanation for the observed heterogeneity is a combination of ecological factors\u2014trophic interactions, species incumbency and competitive exclusion by opportunists\u2014and 'chance'. The question of whether the post-impact recovery of marine productivity was delayed closer to the crater has a bearing on the predictability of future patterns of recovery in anthropogenically perturbed ecosystems. If there is a relationship between the distance from the impact and the recovery of marine productivity, we would expect recovery rates to be slowest in the crater itself. Here we present a record of foraminifera, calcareous nannoplankton, trace fossils and elemental abundance data from within the Chicxulub crater, dated to approximately the first 200 kyr of the Palaeocene. We show that life reappeared in the basin just years after the impact and a high-productivity ecosystem was established within 30 kyr, which indicates that proximity to the impact did not delay recovery and that there was therefore no impact-related environmental control on recovery. Ecological processes probably controlled the recovery of productivity after the Cretaceous/Palaeogene mass extinction and are therefore likely to be important for the response of the ocean ecosystem to other rapid extinction events.", "date": "2018-06-14", "date_type": "published", "publication": "Nature", "volume": "558", "number": "7709", "publisher": "Nature Publishing Group", "pagerange": "288-291", "id_number": "CaltechAUTHORS:20180322-124636829", "issn": "0028-0836", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180322-124636829", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "European Consortium for Ocean Research Drilling (ECORD)" }, { "agency": "International Continental Drilling Program" }, { "agency": "Yucat\u00e1n State Government" }, { "agency": "Universidad Nacional Aut\u00f3noma de M\u00e9xico (UNAM)" }, { "agency": "NSF", "grant_number": "OCE-1737351" }, { "agency": "NASA", "grant_number": "NNX16AJ60G" }, { "agency": "Secretar\u00eda de Estado de Investigaci\u00f3n, Desarrollo e Innovaci\u00f3n", "grant_number": "CGL2015-66835-P" }, { "agency": "Universidad de Granada", "grant_number": "UCE-2016-05" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/s41586-018-0163-6", "pmcid": "PMC6058194", "primary_object": { "basename": "41586_2018_163_MOESM2_ESM.pdf", "url": "https://authors.library.caltech.edu/records/yxt5c-gpr72/files/41586_2018_163_MOESM2_ESM.pdf" }, "related_objects": [ { "basename": "nihms956943.pdf", "url": "https://authors.library.caltech.edu/records/yxt5c-gpr72/files/nihms956943.pdf" }, { "basename": "41586_2018_163_Fig4_ESM.jpg", "url": "https://authors.library.caltech.edu/records/yxt5c-gpr72/files/41586_2018_163_Fig4_ESM.jpg" }, { "basename": "41586_2018_163_Fig8_ESM.jpg", "url": "https://authors.library.caltech.edu/records/yxt5c-gpr72/files/41586_2018_163_Fig8_ESM.jpg" }, { "basename": "41586_2018_163_MOESM1_ESM.pdf", "url": "https://authors.library.caltech.edu/records/yxt5c-gpr72/files/41586_2018_163_MOESM1_ESM.pdf" }, { "basename": "41586_2018_163_MOESM5_ESM.xlsx", "url": "https://authors.library.caltech.edu/records/yxt5c-gpr72/files/41586_2018_163_MOESM5_ESM.xlsx" }, { "basename": "41586_2018_163_Fig6_ESM.jpg", "url": "https://authors.library.caltech.edu/records/yxt5c-gpr72/files/41586_2018_163_Fig6_ESM.jpg" }, { "basename": "41586_2018_163_Fig7_ESM.jpg", "url": "https://authors.library.caltech.edu/records/yxt5c-gpr72/files/41586_2018_163_Fig7_ESM.jpg" }, { "basename": "41586_2018_163_Fig9_ESM.jpg", "url": "https://authors.library.caltech.edu/records/yxt5c-gpr72/files/41586_2018_163_Fig9_ESM.jpg" }, { "basename": "41586_2018_163_MOESM3_ESM.xlsx", "url": "https://authors.library.caltech.edu/records/yxt5c-gpr72/files/41586_2018_163_MOESM3_ESM.xlsx" }, { "basename": "41586_2018_163_Tab1_ESM.jpg", "url": "https://authors.library.caltech.edu/records/yxt5c-gpr72/files/41586_2018_163_Tab1_ESM.jpg" }, { "basename": "41586_2018_163_Fig5_ESM.jpg", "url": "https://authors.library.caltech.edu/records/yxt5c-gpr72/files/41586_2018_163_Fig5_ESM.jpg" }, { "basename": "41586_2018_163_MOESM4_ESM.xlsx", "url": "https://authors.library.caltech.edu/records/yxt5c-gpr72/files/41586_2018_163_MOESM4_ESM.xlsx" } ], "resource_type": "article", "pub_year": "2018", "author_list": "Lowery, Christopher M. and Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/10pa0-mdx67", "eprint_id": 85197, "eprint_status": "archive", "datestamp": "2023-08-22 01:55:35", "lastmod": "2023-10-18 17:57:23", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Monteiro-H-S", "name": { "family": "Monteiro", "given": "H. S." }, "orcid": "0000-0002-3797-1869" }, { "id": "Vasconcelos-P-M-P", "name": { "family": "Vasconcelos", "given": "P. M. P." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Lopes-C-A-M", "name": { "family": "Lopes", "given": "C. A. M." } } ] }, "title": "Age and evolution of diachronous erosion surfaces in the Amazon: combining (U-Th)/He and cosmogenic ^3He records", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2018 Published by Elsevier Ltd. \n\nReceived 24 July 2017, Accepted 28 February 2018, Available online 8 March 2018. \n\nWe thank present and past colleagues from Vale, particularly Carlos Monte Lopes, Luzimar Rego, Clovis Maurity, Paulo S\u00e9rgio Machado, Fernando Greco, Fernando Martins, Henrique Meireles, Carlos Augusto de Medeiros Filho, Augusto Kishida, and Felipe Porto for field support and heated discussions on the evolution of Caraj\u00e1s region. This project was funded by the Australian Research Council (ARC Discovery Grant DP160104988), Australian Research Council (ARC Linkage Grant LP4001008005), and the Brazilian Research Council (CNPq), which sponsored Hevelyn Monteiro's PhD studies. Electronic appendices are available at doi: 10.17632/fgtdnjw3mn.2", "abstract": "(U-Th)/He geochronology of two weathered plateaus in the Caraj\u00e1s Mountains, Par\u00e1, Brazil, reveals a history of weathering spanning from ca. 80 Ma to the present for this high elevation (\u223c720 m) land surface. Cosmogenic ^3He measurements of hematite pebbles and blocks cemented onto the plateaus at two sites, N1 and S11D, yield erosion rates as low as 0.09 and 0.08 m.Ma^(-1), respectively. Thus, these results confirm that the plateau surfaces are nearly immune to physical erosion for tens of millions of years. (U-Th)/He geochronology of ferruginous duricrusts blanketing the low elevation (250-100 m) plains surrounding the Caraj\u00e1s Mountains yield results consistently younger than \u223c10 Ma. The geochronology results also reveal that the low elevation plain is diachronous, becoming progressively younger towards the receding plateaus. The spatial distribution of (U-Th)/He ages permits reconstruction of the history of scarp retreat for the Caraj\u00e1s landscape, showing that scarp retreat along major river valleys may have been as fast as 20 km.Ma^(-1) during tectonically active and humid periods in the Cenozoic. The cessation of scarp retreat at some sites suggests that metamorphosed banded iron-formations and quartzites provide effective barriers to retreating escarpments, helping to preserve some of the oldest continuously exposed land surfaces on Earth.", "date": "2018-05-15", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "229", "publisher": "Elsevier", "pagerange": "162-183", "id_number": "CaltechAUTHORS:20180308-091037841", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180308-091037841", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Australian Research Council", "grant_number": "DP160104988" }, { "agency": "Australian Research Council", "grant_number": "LP4001008005" }, { "agency": "Conselho Nacional de Desenvolvimento Cient\u00edfico e Tecnol\u00f3gico (CNPq)" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2018.02.045", "resource_type": "article", "pub_year": "2018", "author_list": "Monteiro, H. S.; Vasconcelos, P. M. P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/an1h8-1ts16", "eprint_id": 83921, "eprint_status": "archive", "datestamp": "2023-08-22 01:50:20", "lastmod": "2023-10-18 14:30:59", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Price-J-B", "name": { "family": "Price", "given": "Jason B." }, "orcid": "0000-0001-9865-603X" }, { "id": "Wernicke-B-P", "name": { "family": "Wernicke", "given": "Brian P." }, "orcid": "0000-0002-7659-8358" }, { "id": "Cosca-M-A", "name": { "family": "Cosca", "given": "Michael A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Thermochronometry across the Austroalpine-Pennine boundary, Central Alps, Switzerland: Orogen-perpendicular normal fault slip on a major 'overthrust' and its implications for orogenesis", "ispublished": "pub", "full_text_status": "public", "note": "Published - Price_et_al-2018-Tectonics.pdf
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Supplemental Material - tect20680-sup-0002-2017TC004619_S1.docx
", "abstract": "Fifty-one new and 309 published thermochronometric ages (nine systems with closure temperatures ranging from ~450 to 70\u00b0C) from the Graub\u00fcnden region of the Central Alps demonstrate that a pronounced thermal mismatch between the Austroalpine allochthon (Alpine \"orogenic lid\") and the Pennine zone persisted until at least 29 Ma and, allowably, until circa 18 Ma. The observed mismatch supports previous suggestions that the famous \"overthrust\" between the Austroalpine allochthon and the Pennine zone, historically regarded as primarily an Eocene top-north thrust fault, is in fact primarily an Oligocene-Miocene normal fault that has a minimum of 60 km of displacement with top-south or top-southeast sense of shear. Two hallmarks of Alpine geology, deposition of the foredeep Molasse and emplacement of the Helvetic nappes, appear to be coeval, peripheral manifestations of crustal thickening via the interposition of the Pennine zone as a northward intruding wedge between the Austroalpine \"lid\" and the European cratonic margin, with the Helvetic system (European margin) acting as the \"floor\" of the wedge. We presume the Penninic wedge is driven by the buoyant rise of subducted crust no longer able to remain attached to the descending slab. If so, emplacement of the Pennine wedge could have occurred mainly after Adria was juxtaposed against cratonic Europe.", "date": "2018-03", "date_type": "published", "publication": "Tectonics", "volume": "37", "number": "3", "publisher": "American Geophysical Union", "pagerange": "724-757", "id_number": "CaltechAUTHORS:20171214-105427229", "issn": "0278-7407", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171214-105427229", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1451055" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/2017TC004619", "primary_object": { "basename": "Price_et_al-2018-Tectonics.pdf", "url": "https://authors.library.caltech.edu/records/an1h8-1ts16/files/Price_et_al-2018-Tectonics.pdf" }, "related_objects": [ { "basename": "tect20680-sup-0001-2017TC004619_S4.xls", "url": "https://authors.library.caltech.edu/records/an1h8-1ts16/files/tect20680-sup-0001-2017TC004619_S4.xls" }, { "basename": "tect20680-sup-0002-2017TC004619_S1.docx", "url": "https://authors.library.caltech.edu/records/an1h8-1ts16/files/tect20680-sup-0002-2017TC004619_S1.docx" } ], "resource_type": "article", "pub_year": "2018", "author_list": "Price, Jason B.; Wernicke, Brian P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/c8pdv-drx53", "eprint_id": 84577, "eprint_status": "archive", "datestamp": "2023-08-22 01:48:31", "lastmod": "2023-10-18 16:22:46", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Monteiro-H-S", "name": { "family": "Monteiro", "given": "H. S." }, "orcid": "0000-0002-3797-1869" }, { "id": "Vasconcelos-P-M-P", "name": { "family": "Vasconcelos", "given": "P. M. P." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "A combined (U-Th)/He and cosmogenic ^3He record of landscape armoring by biogeochemical iron cycling", "ispublished": "pub", "full_text_status": "public", "keywords": "(U-Th)/He dating; canga; Cosmogenic 3He; BIF landscapes", "note": "\u00a9 2018 American Geophysical Union. \n\nReceived 8 MAR 2017; Accepted 5 DEC 2017; Accepted article online 29 JAN 2018; Published online 20 FEB 2018. \n\nWe thank Shirley Barros, Carolina Silva, MBR and Vale for logistic support; UQ\u2010CMM staff for help during microanalysis; and, particularly, Lindsey Hedges for help and guidance during (U\u2010Th)/He analyses. We also thank D. Granger, A. Ault, M. Schulz, and two Editors from JGR for their constructive comments and suggestions. This project was supported by the Australian Research Council (ARC Discovery grant DP160104988) to Paulo Vasconcelos and Kenneth Farley and the Brazilian Research Council (CNPq), which sponsored Hevelyn Monteiro's PhD studies. Geochronological data set is available at http://dx.doi.org/10.1594/IEDA/100730.\n\nPublished - Monteiro_et_al-2018-Journal_of_Geophysical_Research__Earth_Surface.pdf
", "abstract": "(U\u2010Th)/He geochronology and cosmogenic ^3He in iron oxides reveal mineral precipitation ages as old as 55 Ma and exposure ages greater than 5 Ma for canga\u2010cemented plateaus in the Quadril\u00e1tero Ferr\u00edfero, Brazil, showing that lateritic profiles overlying banded iron\u2010formation (BIF) landscapes in tropical regions have a long history of surface exposure. The long\u2010term erosion history obtained from cosmogenic ^3He on BIF plateaus confirms that relic surfaces persist in the landscape for millions of years. Combined ^3He and (U\u2010Th)/He dating shows that cangas are preferentially goethite cemented by biogeochemical reactions in the subsurface. Importantly, pebbles of hematite\u2010magnetite in colluvia or shallow creeks draining the canga\u2010cemented plateaus record a much longer exposure history than in situ canga blocks, showing that even older duricrusts, now eroded, once blanketed these plateaus. Physically stable but biogeochemically dynamic, cangas armor the landscape by pervasive and recurrent iron cycling and cementation, slowing down the delivery of weathered BIF or friable hematite\u2013magnetite ore to erosion.", "date": "2018-02", "date_type": "published", "publication": "Journal of Geophysical Research. Earth Surface", "volume": "123", "number": "2", "publisher": "American Geophysical Union", "pagerange": "298-323", "id_number": "CaltechAUTHORS:20180130-105653677", "issn": "2169-9003", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180130-105653677", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Australian Research Council", "grant_number": "DP160104988" }, { "agency": "Conselho Nacional de Desenvolvimento Cient\u00edfico e Tecnol\u00f3gico (CNPq)" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/2017JF004282", "primary_object": { "basename": "Monteiro_et_al-2018-Journal_of_Geophysical_Research__Earth_Surface.pdf", "url": "https://authors.library.caltech.edu/records/c8pdv-drx53/files/Monteiro_et_al-2018-Journal_of_Geophysical_Research__Earth_Surface.pdf" }, "resource_type": "article", "pub_year": "2018", "author_list": "Monteiro, H. S.; Vasconcelos, P. M. P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/yhxh5-37325", "eprint_id": 83720, "eprint_status": "archive", "datestamp": "2023-08-22 01:44:47", "lastmod": "2023-10-17 23:27:02", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Martin-P-E", "name": { "family": "Martin", "given": "P. E." }, "orcid": "0000-0003-4243-2090" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Baker-M-B", "name": { "family": "Baker", "given": "M. B." } }, { "id": "Malespin-C-A", "name": { "family": "Malespin", "given": "C. A." }, "orcid": "0000-0002-5852-5016" }, { "id": "Schwenzer-S-P", "name": { "family": "Schwenzer", "given": "S. P." }, "orcid": "0000-0002-9608-0759" }, { "id": "Cohen-B-A", "name": { "family": "Cohen", "given": "B. A." }, "orcid": "0000-0001-5896-5903" }, { "id": "Mahaffy-P-R", "name": { "family": "Mahaffy", "given": "P. R." }, "orcid": "0000-0003-1896-1726" }, { "id": "McAdam-A-C", "name": { "family": "McAdam", "given": "A. C." } }, { "id": "Ming-Douglas-W", "name": { "family": "Ming", "given": "D. W." }, "orcid": "0000-0003-0567-8876" }, { "id": "Vasconcelos-P-M", "name": { "family": "Vasconcelos", "given": "P. M." } }, { "id": "Navarro-Gonz\u00e1lez-R", "name": { "family": "Navarro-Gonz\u00e1lez", "given": "R." } } ] }, "title": "A two-step K-Ar experiment on Mars: dating the diagenetic formation of jarosite from Amazonian groundwaters", "ispublished": "pub", "full_text_status": "public", "keywords": "K-Ar; jarosite; diagenetic; Amazonian; Mars; Geochronology", "note": "\u00a9 2017 American Geophysical Union. \n\nReceived 12 SEP 2017; Accepted 27 NOV 2017; Accepted article online 5 DEC 2017; Published online 20 DEC 2017. \n\nWe thank George Rossmann, Tom Bristow, Liz Rampe, Dick Morris, and Paul Asimow for numerous helpful discussions. We are indebted to the MSL science and engineering teams, who made (and continue to make) this work possible. Data contained in this paper are publicly available on the Planetary Data System (PDS; pds.nasa.gov). Funding was provided by NASA.\n\nPublished - Martin_et_al-2017-Journal_of_Geophysical_Research__Planets.pdf
Supplemental Material - jgre20777-sup-0001-2017JE005445_SI.pdf
", "abstract": "Following K-Ar dating of a mudstone and a sandstone, a third sample has been dated by the Curiosity rover exploring Gale Crater. The Mojave 2 mudstone, which contains relatively abundant jarosite, yielded a young K-Ar bulk age of 2.57 \u00b1 0.39 Ga (1\u03c3 precision). A two-step heating experiment was implemented in an effort to resolve the K-Ar ages of primary and secondary mineralogical components within the sample. This technique involves measurement of ^(40)Ar released in low-temperature (500\u00b0C) and high-temperature (930\u00b0C) steps, and a model of the potassium distribution within the mineralogical components of the sample. Using this method, the high-temperature step yields a K-Ar model age of 4.07 \u00b1 0.63 Ga associated with detrital plagioclase, compatible with the age obtained on the Cumberland mudstone by Curiosity. The low-temperature step, associated with jarosite mixed with K-bearing evaporites and/or phyllosilicates, gave a youthful K-Ar model age of 2.12 \u00b1 0.36 Ga. The interpretation of this result is complicated by the potential for argon loss after mineral formation. Comparison with the results on Cumberland and previously published constraints on argon retentivity of the individual phases likely to be present suggests that the formation age of the secondary materials, correcting for plausible extents of argon loss, is still less than 3 Ga, suggesting post-3 Ga aqueous processes occurred in the sediments in Gale Crater. Such a result is inconsistent with K-bearing mineral formation in Gale Lake and instead suggests postdepositional fluid flow at a time after surface fluvial activity on Mars is thought to have largely ceased.", "date": "2017-12", "date_type": "published", "publication": "Journal of Geophysical Research. Planets", "volume": "122", "number": "12", "publisher": "American Geophysical Union", "pagerange": "2803-2818", "id_number": "CaltechAUTHORS:20171206-084713977", "issn": "2169-9097", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171206-084713977", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/2017JE005445", "primary_object": { "basename": "Martin_et_al-2017-Journal_of_Geophysical_Research__Planets.pdf", "url": "https://authors.library.caltech.edu/records/yhxh5-37325/files/Martin_et_al-2017-Journal_of_Geophysical_Research__Planets.pdf" }, "related_objects": [ { "basename": "jgre20777-sup-0001-2017JE005445_SI.pdf", "url": "https://authors.library.caltech.edu/records/yhxh5-37325/files/jgre20777-sup-0001-2017JE005445_SI.pdf" } ], "resource_type": "article", "pub_year": "2017", "author_list": "Martin, P. E.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/xjw96-7y827", "eprint_id": 80908, "eprint_status": "archive", "datestamp": "2023-08-22 01:40:36", "lastmod": "2023-10-17 18:35:37", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Miller-H-B-D", "name": { "family": "Miller", "given": "Hayden B. D." } }, { "id": "Vasconcelos-P-M", "name": { "family": "Vasconcelos", "given": "Paulo M." } }, { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "John M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "A Cenozoic terrestrial paleoclimate record from He dating and stable isotope geochemistry of goethites from Western Australia", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2017 Geological Society of America. \n\nManuscript received 23 January 2017; Revised manuscript received 17 June 2017; Manuscript accepted 21 June 2017. Published: 04 August 2017.", "abstract": "Supergene goethites from the Hamersley region of Western Australia were analyzed for \u03b4^(18)O and the results combined with both new and previously published (U-Th)/He ages to assess the paleoenvironmental signal recorded by surficial goethite in a long-term continental archive. \u0394^(18)O_(goe) values increase monotonically by \u223c3\u2030 between 71 Ma and 5 Ma and appear little affected by changes in temperature or other characteristics of depositional environment. The temporal trend likely reflects the isotopic composition of meteoric water from which the goethite formed, which varied as Australia migrated \u223c3000 km northward over the Cenozoic. Translating age to paleolatitude reveals that the \u03b4^(18)O_(goe) data are consistent with a latitudinal gradient in the \u03b4^(18)O_(precip) that, throughout the Cenozoic, remained largely unchanged from the modern gradient. There is a 5\u2030 offset between the latitudinal trends of \u03b4^(18)O_(goe) and modern precipitation, approximately as expected from the water-goethite fractionation factor. Temporal variation in the \u03b4^(18)O of local meteoric water arising from changes in moisture source or pathway are not evident in the goethites, at least in part because topography is subdued and has evolved little in this tectonically quiescent landscape. Our results provide evidence that the efficiency of water transport from equator to pole that governs the latitudinal \u03b4^(18)O gradient of precipitation has been roughly constant over southern temperate latitudes for the entirety of the Cenozoic.", "date": "2017-10", "date_type": "published", "publication": "Geology", "volume": "45", "number": "10", "publisher": "Geological Society of America", "pagerange": "895-898", "id_number": "CaltechAUTHORS:20170829-133611502", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170829-133611502", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/G38989.1", "resource_type": "article", "pub_year": "2017", "author_list": "Miller, Hayden B. D.; Vasconcelos, Paulo M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/m2qqq-tbs63", "eprint_id": 81667, "eprint_status": "archive", "datestamp": "2023-08-22 01:38:33", "lastmod": "2023-10-17 20:56:41", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Franz-H-B", "name": { "family": "Franz", "given": "H. B." } }, { "id": "Fischer-W-W", "name": { "family": "Fischer", "given": "W. W." }, "orcid": "0000-0002-8836-3054" }, { "id": "Grotzinger-J-P", "name": { "family": "Grotzinger", "given": "J. P." }, "orcid": "0000-0001-9324-1257" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Large sulfur isotope fractionations in Martian sediments at Gale crater", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2017 Macmillan Publishers Limited, part of Springer Nature. \n\nReceived 27 September 2016; Accepted 12 July 2017; Published online 07 August 2017. \n\nThis work was funded by NASA's Mars Exploration Program. The authors thank T. B. Griswold for assistance with figure preparation, B. Franz for editorial support, J. Farquhar for manuscript review, J. Farquhar and A. J. Kaufman for facilitating isotopic analyses of calibrants, and the technical team at the NASA GSFC Planetary Environments Laboratory for laboratory support. \n\nAuthor Contributions: H.B.F. developed analytical methods, calculated and interpreted sulfur isotope ratios, performed calibration experiments, and wrote the manuscript and most of the Supplementary Information. A.C.M. wrote the mineralogy section of the Supplementary Information. H.B.F., A.C.M. and C.A.K. performed supporting laboratory EGA studies. C.F. contributed to analysis of calibration data. D.L.E. calculated theoretical equilibrium fractionation factors for relevant sulfur-bearing species. H.B.F., J.W.D. and R.P. performed ground-truth isotopic analyses of calibrants. All authors participated in discussion of results and/or editing of the manuscript. \n\nThe authors declare no competing financial interests. \n\nData availability: All SAM data are available at the Geosciences Node of NASA's Planetary Data System: http://pds-geosciences.wustl.edu/missions/msl/sam.htm.\n\nSupplemental Material - ngeo3002-s1.pdf
", "abstract": "Variability in the sulfur isotopic composition in sediments can reflect atmospheric, geologic and biological processes. Evidence for ancient fluvio-lacustrine environments at Gale crater on Mars and a lack of efficient crustal recycling mechanisms on the planet suggests a surface environment that was once warm enough to allow the presence of liquid water, at least for discrete periods of time, and implies a greenhouse effect that may have been influenced by sulfur-bearing volcanic gases. Here we report in situ analyses of the sulfur isotopic compositions of SO_2 volatilized from ten sediment samples acquired by NASA's Curiosity rover along a 13\u2009km traverse of Gale crater. We find large variations in sulfur isotopic composition that exceed those measured for Martian meteorites and show both depletion and enrichment in ^(34)S. Measured values of \u03b4^(34)S range from \u221247 \u00b1 14\u2030 to 28 \u00b1 7\u2030, similar to the range typical of terrestrial environments. Although limited geochronological constraints on the stratigraphy traversed by Curiosity are available, we propose that the observed sulfur isotopic signatures at Gale crater can be explained by equilibrium fractionation between sulfate and sulfide in an impact-driven hydrothermal system and atmospheric processing of sulfur-bearing gases during transient warm periods.", "date": "2017-09", "date_type": "published", "publication": "Nature Geoscience", "volume": "10", "number": "9", "publisher": "Nature Publishing Group", "pagerange": "658-662", "id_number": "CaltechAUTHORS:20170921-091550876", "issn": "1752-0894", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170921-091550876", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/NGEO3002", "primary_object": { "basename": "ngeo3002-s1.pdf", "url": "https://authors.library.caltech.edu/records/m2qqq-tbs63/files/ngeo3002-s1.pdf" }, "resource_type": "article", "pub_year": "2017", "author_list": "Franz, H. B.; Fischer, W. W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/mwbx4-zxq56", "eprint_id": 79020, "eprint_status": "archive", "datestamp": "2023-08-22 01:32:36", "lastmod": "2023-10-26 14:32:27", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Montanari-A", "name": { "family": "Montanari", "given": "Alessandro" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Ken" }, "orcid": "0000-0002-7846-7546" }, { "id": "Claeys-P", "name": { "family": "Claeys", "given": "Philippe" }, "orcid": "0000-0002-4585-7687" }, { "id": "De-Vleeschouwer-D", "name": { "family": "De Vleeschouwer", "given": "David" }, "orcid": "0000-0002-3323-807X" }, { "id": "de-Winter-N", "name": { "family": "de Winter", "given": "Niels" } }, { "id": "Vansteenberge-S", "name": { "family": "Vansteenberge", "given": "Stef" } }, { "id": "Sinnesael-M", "name": { "family": "Sinnesael", "given": "Matthias" } }, { "id": "Koeberl-C", "name": { "family": "Koeberl", "given": "Christian" } } ] }, "title": "Stratigraphic record of the asteroidal Veritas breakup in the Tortonian Monte dei Corvi section (Ancona, Italy)", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2017 Geological Society of America. \n\nReceived: 21 Dec 2016; Revised: 24 Jan 2017; Accepted: 19 Apr 2017. \n\nThis research was supported by the Research Foundation Flanders (FWO grants G0B8513N and G009113N), the Hercules Foundation for the upgrade of the Vrije Universiteit Brussel Stable Isotope Laboratory (Philippe Claeys), and support from the Flemish Agency for Innovation by Science and Technology (IWT; to Niels De Winter). We thank the Association \"Le Montagne di San Francesco\" of Coldigioco for logistical support while working on this research project. We would also like to thank Beatrice Cecchin for helping to collect the samples in the Monte dei Corvi Beach section in 2009, and preparing them for laboratory analyses at the University of Vienna. A special thanks goes to Timothy Herbert and Alexandrina Tzanova (Brown University, Rhode Island) for providing the sea-surface temperature data of the Monte dei Corvi Beach section, Laura Cleaveland-Peterson (Luther College, Iowa) for providing the raw magnetic susceptibility data from the Monte dei Corvi section, Mario Sprovieri (L'Istituto per l'Ambiente Marino Costiero del Consiglio Nazionale delle Ricerche [CNR-IAMC], Italy) for providing the raw oxygen and carbon stable isotope data from the Cenomanian\u2013Turonian section of Bottaccione, and Heather Stoll (University of Oviedo, Spain) for providing the raw oxygen and carbon stable isotope data from the Cenomanian\u2013Turonian section of\nContessa. We would like to thank David Bice, Jan Smit, Maurizio Mainiero, and Rodolfo Coccioni for sharing their knowledge and discussions about the stratigraphic succession at Monte dei Corvi. Last, but not least, we would like to thank David Bice, Birger Schmitz, and two other undisclosed GSA Bulletin reviewers, as well as Editors H. Dypvik and A. Cavosie, for their useful and constructive comments and suggestions, which greatly helped us to improve the form and contents of this paper.", "abstract": "The discovery of elevated concentrations of the cosmogenic radionuclide ^3He in deep-sea sediments from Ocean Drilling Program (ODP) Site 926 (Atlantic Ocean) and ODP Site 757 (Indian Ocean) points toward accretion of extraterrestrial matter, probably as a result of the catastrophic disruption of a large asteroid that produced the Veritas family of asteroids at ca. 8.3 \u00b1 0.5 Ma, and which may have had important effects on the global climatic and ecologic systems. Here, we investigated the signatures possibly related to the Veritas event by performing a high-resolution multiproxy stratigraphic analysis through the late Tortonian\u2212early Messinian Monte dei Corvi section near Ancona, Italy. Closely spaced bulk-rock samples through a 36-m-thick section, approximately spanning from ca. 9.9 Ma to ca. 6.4 Ma, show an \u223c5-fold ^3He anomaly starting at ca. 8.5 Ma and returning to background values at ca. 6.9 Ma, confirming the global nature of the event. We then analyzed, at 5 cm intervals, bulk-rock samples for sedimentary and environmental proxies such as magnetic susceptibility, calcium carbonate content, total organic carbon, and bulk carbonate \u03b4^(18)O and \u03b4^(13)C, through a 21-m-thick section encompassing the ^3He anomaly. Available high-resolution sea-surface temperature data (via alkenone analyses) for this site show a temperature decrease starting exactly at the inception of the ^3He anomaly. Cyclostratigraphic fast-Fourier-transform spectral analyses of the proxies indicate an age of 8.47 \u00b1 0.05 Ma for the inception of the ^3He anomaly. A search for impact ejecta (analogous to what is present in the late Eocene, where both a ^3He anomaly and large-scale impact events are recorded) was not successful. Detailed cyclostratigraphic analyses of our data suggest that the changes in the stable isotope series and environmental proxy series through this late Tortonian time interval had a common forcing agent, and that perturbations of orbitally forced climate cycles are present exactly through the interval with the enhanced influx of extraterrestrial ^3He. Thus, the chemostratigraphic evidence for a collisional event that created the Veritas family of asteroids, coinciding with climate perturbations on Earth, suggests yet another form of interaction between Earth and the solar system.", "date": "2017-06", "date_type": "published", "publication": "Geological Society of America Bulletin", "volume": "129", "number": "9-10", "publisher": "Geological Society of America", "pagerange": "1357-1376", "id_number": "CaltechAUTHORS:20170712-140641645", "issn": "0016-7606", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170712-140641645", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Fonds Wetenschappelijk Onderzoek - Vlaanderen (FWO)", "grant_number": "G0B8513N" }, { "agency": "Fonds Wetenschappelijk Onderzoek - Vlaanderen (FWO)", "grant_number": "G009113N" }, { "agency": "Hercules Foundation" }, { "agency": "Agency for Innovation by Science and Technology (Belgium)" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/B31476.1", "resource_type": "article", "pub_year": "2017", "author_list": "Montanari, Alessandro; Farley, Ken; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/pqev1-pyc61", "eprint_id": 75297, "eprint_status": "archive", "datestamp": "2023-08-22 01:30:58", "lastmod": "2023-10-25 14:55:39", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hofmann-F", "name": { "family": "Hofmann", "given": "Florian" } }, { "id": "Reichenbacher-B", "name": { "family": "Reichenbacher", "given": "Bettina" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Evidence for >5 Ma paleo-exposure of an Eocene\u2013Miocene paleosol of the Bohnerz Formation, Switzerland", "ispublished": "pub", "full_text_status": "public", "keywords": "Bohnerz; paleosol; goethite pisolith; (U\u2013Th)/He dating; cosmogenic 3He; paleo-exposure", "note": "\u00a9 2017 Elsevier B.V. \n\nReceived 6 November 2016; Received in revised form 22 February 2017; Accepted 24 February 2017. \n\nWe thank Daniel K\u00e4lin for sharing his knowledge of local geology in the field. Abbey Nastan is thanked for her valuable help in the field. Two anonymous reviewers provided thoughtful comments on the manuscript.\n\nSupplemental Material - mmc1.pdf
", "abstract": "We obtained (U\u2013Th)/He formation ages and cosmogenic ^3He concentrations for pisoliths from a paleosol of the Bohnerz Formation (Siderolithic) of Central Europe. The paleosol is exposed in the Almenb\u00fchl quarry near Lohn, Canton Schaffhausen, Switzerland. The paleosol consists of red clay of 3\u20134 m thickness developed on deeply weathered Jurassic limestone and overlain by Early Miocene conglomerates. The (U\u2013Th)/He formation ages of the pisoliths are between 50 Ma and 8 Ma, with most ages being older than 17 Ma. There is a sharp decline in the frequency of ages at the time of burial of the paleosol at 17 Ma. These ages are inconsistent with the previous assumption that the Bohnerz Formation formed in a Cretaceous to Early Eocene laterite in a tropical climate. We propose that the Bohnerz Formation more closely resembles Terra Rossa soils, which do not require a tropical climate to form. The ^3He concentration in the pisoliths is roughly constant with depth throughout the paleosol at 300 Matoms/g. We interpret this as the result of soil convection during cosmic ray exposure. The minimum exposure duration at the surface of the paleosol is \u223c5 Ma. A simple model of soil convection shows that the true exposure duration of the paleosol is approximately 10\u201320 Ma. These results indicate that the clay soils of the Bohnerz formation were continuously exposed at the surface for millions of years. Since the paleosol was covered by conglomerate since 17 Ma, the ^3He measured here was produced by cosmic ray exposure before burial. Cosmogenic ^3He concentrations measured in fine-grained soil iron-oxides (<1 \u03bcm) are similar to those measured in pisoliths. This might indicate that fine-grained iron-oxides are retentive to helium and might be used for studying the formation and cosmic ray exposure of modern soils and paleosols.", "date": "2017-05-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "465", "publisher": "Elsevier", "pagerange": "168-175", "id_number": "CaltechAUTHORS:20170322-073310444", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170322-073310444", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2017.02.042", "primary_object": { "basename": "mmc1.pdf", "url": "https://authors.library.caltech.edu/records/pqev1-pyc61/files/mmc1.pdf" }, "resource_type": "article", "pub_year": "2017", "author_list": "Hofmann, Florian; Reichenbacher, Bettina; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/tyqkk-ekf06", "eprint_id": 72102, "eprint_status": "archive", "datestamp": "2023-08-19 01:13:19", "lastmod": "2023-10-23 17:55:23", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sousa-F-J", "name": { "family": "Sousa", "given": "Francis J." }, "orcid": "0000-0003-1623-4023" }, { "id": "Saleeby-J-B", "name": { "family": "Saleeby", "given": "Jason" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Unruh-J-R", "name": { "family": "Unruh", "given": "Jeffrey R." } }, { "id": "Lloyd-M-K", "name": { "family": "Lloyd", "given": "Max K." }, "orcid": "0000-0001-9367-2698" } ] }, "title": "The southern Sierra Nevada pediment, central California", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2016 Geological Society of America. \n\nReceived 24 May 2016. Revision received 17 August 2016. Accepted 20 October 2016. First Published on November 11, 2016. \n\nThemed Issue: Origin and Evolution of the Sierra Nevada and Walker Lane. Guest editors: Keith D. Putirka and Cathy J. Busby. \n\nWe thank Kerry Gallagher for assistance with setting up QTQt runs and Lindsey Hedges for help with sample preparation, analyses, and a life full of friendship. Thanks to Guest Associate Editor Cathy Busby and two anonymous reviewers for constructive reviews of this manuscript. This work was partially supported by the Gordon and Betty Moore Foundation through grant GBMF #423.01 to the Caltech Tectonics Observatory.", "abstract": "The southern Sierra Nevada foothills, central California (USA), expose a fossil pre\u201340 Ma bedrock pediment which we call the southern Sierra Nevada pediment. We document this landscape with multiple types of data, and also report new apatite ^4He/^3He, (U-Th)/He, and zircon (U-Th)/He data from the pediment that significantly expand the spatial extent of southern Sierra low-temperature thermochronology data westward into the foothills. Applying recently published thermal modeling software for thermochronologic data, which uses a transdimensional Bayesian Monte Carlo Markov chain statistical approach, we tightly constrain the thermal history of the southern Sierra Nevada pediment. Integrating this thermal history with numerous previously published data sets from across the southern Sierra, we present a chronology of tectonic and landscape evolution of the southern Sierra Nevada. For the first time we cover the entire width of the range, integrate the numerous published data sets into a single coherent geologic story, and link each phase of this story to a potential mechanism.\nModeling results are consistent with a three-phase cooling history for the southern Sierra Nevada pediment. Rapid exhumation ca. 95\u201385 Ma resulted in cooling to between 55 \u00b0C and 100 \u00b0C. Following this, slow cooling to surface conditions occurred from 85 Ma to 40 Ma at rates consistent with those estimated for the axial southern Sierra during the same time period by previous studies. Little if any additional cooling occurred post\u201340 Ma. We hypothesize that a thin sedimentary cover protected the 40 Ma bedrock landscape through much of the last 40 m.y., and that this cover eroded away post\u201310 Ma, re-exhuming the southern Sierra Nevada pediment as a fossil pre\u201340 Ma landscape. Each of these three phases of cooling links to a distinct tectonic or geomorphic regime, including the profound rapid exhumation of the southern Sierra Nevada\u2013Mojave segment of the Cretaceous arc due to subduction of a large oceanic plateau, the formation of the low-relief landscape of the high-elevation areas of the southern Sierra Nevada with more limited tectonic forcing, and Eocene activity on the Western Sierra Fault System.", "date": "2017-02", "date_type": "published", "publication": "Geosphere", "volume": "13", "number": "1", "publisher": "Geological Society of America", "pagerange": "82-101", "id_number": "CaltechAUTHORS:20161117-085737387", "issn": "1553-040X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161117-085737387", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation", "grant_number": "423.01" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/GES01369.1", "resource_type": "article", "pub_year": "2017", "author_list": "Sousa, Francis J.; Saleeby, Jason; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/nd0nr-njf97", "eprint_id": 73168, "eprint_status": "archive", "datestamp": "2023-08-22 19:19:58", "lastmod": "2023-10-24 15:05:31", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Riffel-S-B", "name": { "family": "Riffel", "given": "Silvana B." } }, { "id": "Vasconcelos-P-M", "name": { "family": "Vasconcelos", "given": "Paulo M." } }, { "id": "Carmo-I-O", "name": { "family": "Carmo", "given": "Isabela O." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Goethite (U\u2013Th)/He geochronology and precipitation mechanisms during weathering of basalts", "ispublished": "pub", "full_text_status": "public", "keywords": "Weathering geochronology; (U\u2013Th)/He; Goethite; Paran\u00e1 Continental Flood Basalts; Landscape evolution", "note": "\u00a9 2016 Elsevier B.V. \n\nReceived in revised form 30 March 2016; Accepted 31 March 2016; Available online 11 April 2016. \n\nThe authors are grateful for the financial support from CAPES (PhD scholarship 4862-06-6) and CNPq (postdoctoral fellowship), and the logistic and financial support for fieldwork from PETROBRAS/CENPES. We thank ANSTO grants to A. Seeber and P. Vasconcelos for access to the Tsukuba and Australian synchrotrons; A. Seeber for the synchrotron analysis and A. Mostert for the Rietveld refinement of the synchrotron results. This work benefited from editorial comments from Prof. Francois Chaboux and in-depth reviews by H. Handley, P. Reiners, and the anonymous reviewer, whose corrections and suggestions greatly helped to improve the final version of the manuscript.\n\nSupplemental Material - mmc1.xlsx
Supplemental Material - mmc2.kml
", "abstract": "(U\u2013Th)/He geochronology of 33 goethite grains from in situ ferruginous duricrusts overlying the Paran\u00e1 flood basalt in the Guarapuava region, Paran\u00e1, Brazil, reveals ages ranging from 3.6 \u00b1 0.4 to 0.4 \u00b1 0.1 Ma. Thirty-one grains from detrital fragments of ferruginous duricrust yield ages in the 6.2 \u00b1 0.6 to 0.7 \u00b1 0.1 Ma range. The results show that goethites from detrital blocks are generally older than those from the in situ ferruginous layers and that all the goethites from the Guarapuava sites are relatively young (\u2264 6.2 \u00b1 0.6 Ma). Goethites show variable U and Th contents depending on the mode of precipitation. Goethite that forms by progressive ferrugization and pseudomorphic replacement of basalts are rich in Th, U-poor, contain various mineral inclusions (e.g., kaolinite, rutile, ilmenite) and display a distinct \"checkered\" appearance. Colloform goethite precipitated within cavities and desiccation cracks contain higher U, show low Th/U values, and are free of mineral contaminants, suggesting direct precipitation from solution. The geochronological results reveal a dynamic evolution for the soils overlying the Paran\u00e1 basalt, where recurrent duricrust formation and dismantling lead to the evolution of regional colluvial soil profiles while simultaneously preventing the evolution of chemically stratified lateritic weathering profiles. The modes of formation and U, Th, and He contents of goethite at Guarapuava provide useful constraints on the expected compositions and modes of formation of goethite formed on basaltic soils on Mars.", "date": "2016-12-23", "date_type": "published", "publication": "Chemical Geology", "volume": "446", "publisher": "Elsevier", "pagerange": "18-32", "id_number": "CaltechAUTHORS:20170103-091501350", "issn": "0009-2541", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170103-091501350", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior (CAPES)", "grant_number": "4862-06-6" }, { "agency": "Conselho Nacional de Desenvolvimento Cient\u00edfico e Tecnol\u00f3gico (CNPq)" }, { "agency": "PETROBRAS/CENPES" }, { "agency": "Australian Nuclear Science and Technology Organisation (ANSTO)" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.chemgeo.2016.03.033", "primary_object": { "basename": "mmc1.xlsx", "url": "https://authors.library.caltech.edu/records/nd0nr-njf97/files/mmc1.xlsx" }, "related_objects": [ { "basename": "mmc2.kml", "url": "https://authors.library.caltech.edu/records/nd0nr-njf97/files/mmc2.kml" } ], "resource_type": "article", "pub_year": "2016", "author_list": "Riffel, Silvana B.; Vasconcelos, Paulo M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/kbv9v-fmw55", "eprint_id": 71199, "eprint_status": "archive", "datestamp": "2023-08-22 18:46:55", "lastmod": "2023-10-23 15:28:43", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vasconcelos-P-M", "name": { "family": "Vasconcelos", "given": "P. M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Malespin-C-A", "name": { "family": "Malespin", "given": "C. A." }, "orcid": "0000-0002-5852-5016" }, { "id": "Mahaffy-P-R", "name": { "family": "Mahaffy", "given": "P." }, "orcid": "0000-0003-1896-1726" }, { "id": "Ming-Douglas-W", "name": { "family": "Ming", "given": "D." }, "orcid": "0000-0003-0567-8876" }, { "id": "McLennan-S-M", "name": { "family": "McLennan", "given": "S. M." }, "orcid": "0000-0003-4259-7178" }, { "id": "Hurowitz-J-A", "name": { "family": "Hurowitz", "given": "J. A." }, "orcid": "0000-0002-5857-8652" }, { "id": "Rice-M-S", "name": { "family": "Rice", "given": "Melissa S." }, "orcid": "0000-0002-8370-4139" } ] }, "title": "Discordant K-Ar and Young Exposure Dates for the Windjana sandstone, Kimberley, Gale Crater, Mars", "ispublished": "pub", "full_text_status": "public", "keywords": "Mars; 36Ar; K-Ar; 3He; 21Ne", "note": "\u00a9 2016 American Geophysical Union. \n\nReceived 12 FEB 2016; Accepted 4 OCT 2016; Accepted article online 17 OCT 2016; Published online 27 OCT 2016. \n\nSpecial Section: The Mars Science Laboratory Rover Mission (Curiosity) at The Kimberley, Gale Crater, Mars. \n\nThe authors thank the Mars Science Laboratory Project teams for an effective and successful mission. Some of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Data presented in this paper are archived in the Planetary Data System (pds.nasa.gov).\n\nPublished - Vasconcelos_et_al-2016-Journal_of_Geophysical_Research__Planets.pdf
Accepted Version - jgre20600.pdf
", "abstract": "K-Ar and noble gas surface exposure age measurements were carried out on the Windjana sandstone, Kimberley region, Gale Crater, Mars, by using the Sample Analysis at Mars instrument on the Curiosity rover. The sandstone is unusually rich in sanidine, as determined by CheMin X-ray diffraction, contributing to the high K_2O concentration of 3.09\u2009\u00b1\u20090.20\u2009wt % measured by Alpha-Particle X-ray Spectrometer analysis. A sandstone aliquot heated to ~915\u00b0C yielded a K-Ar age of 627\u2009\u00b1\u200950\u2009Ma. Reheating this aliquot yielded no additional Ar. A second aliquot heated in the same way yielded a much higher K-Ar age of 1710\u2009\u00b1\u2009110\u2009Ma. These data suggest incomplete Ar extraction from a rock with a K-Ar age older than 1710\u2009Ma. Incomplete extraction at ~900\u00b0C is not surprising for a rock with a large fraction of K carried by Ar-retentive K-feldspar. Likely, variability in the exact temperature achieved by the sample from run to run, uncertainties in sample mass estimation, and possible mineral fractionation during transport and storage prior to analysis may contribute to these discrepant data. Cosmic ray exposure ages from ^3He and ^(21)Ne in the two aliquots are minimum values given the possibility of incomplete extraction. However, the general similarity between the ^3He (57\u2009\u00b1\u200949 and 18\u2009\u00b1\u200932\u2009Ma, mean 30\u2009Ma) and ^(21)Ne (2\u2009\u00b1\u200932 and 83\u2009\u00b1\u200924\u2009Ma, mean 54\u2009Ma) exposure ages provides no evidence for underextraction. The implied erosion rate at the Kimberley location is similar to that reported at the nearby Yellowknife Bay outcrop.", "date": "2016-10", "date_type": "published", "publication": "Journal of Geophysical Research. Planets", "volume": "121", "number": "10", "publisher": "American Geophysical Union", "pagerange": "2176-2192", "id_number": "CaltechAUTHORS:20161018-073743780", "issn": "2169-9097", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161018-073743780", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/2016JE005017", "primary_object": { "basename": "Vasconcelos_et_al-2016-Journal_of_Geophysical_Research__Planets.pdf", "url": "https://authors.library.caltech.edu/records/kbv9v-fmw55/files/Vasconcelos_et_al-2016-Journal_of_Geophysical_Research__Planets.pdf" }, "related_objects": [ { "basename": "jgre20600.pdf", "url": "https://authors.library.caltech.edu/records/kbv9v-fmw55/files/jgre20600.pdf" } ], "resource_type": "article", "pub_year": "2016", "author_list": "Vasconcelos, P. M.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/jp6c1-n2g81", "eprint_id": 70402, "eprint_status": "archive", "datestamp": "2023-08-22 18:46:32", "lastmod": "2024-02-02 21:05:57", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ehlmann-B-L", "name": { "family": "Ehlmann", "given": "B. L." }, "orcid": "0000-0002-2745-3240" }, { "id": "Anderson-F-S", "name": { "family": "Anderson", "given": "F. S." } }, { "id": "Andrews-Hanna-J-C", "name": { "family": "Andrews-Hanna", "given": "J." } }, { "id": "Catling-D-C", "name": { "family": "Catling", "given": "D. C." } }, { "id": "Christensen-P-R", "name": { "family": "Christensen", "given": "P. R." } }, { "id": "Cohen-B-A", "name": { "family": "Cohen", "given": "B. A." }, "orcid": "0000-0001-5896-5903" }, { "id": "Dressing-C-D", "name": { "family": "Dressing", "given": "C. D." }, "orcid": "0000-0001-8189-0233" }, { "id": "Edwards-C-S", "name": { "family": "Edwards", "given": "C. S." } }, { "id": "Elkins-Tanton-L-T", "name": { "family": "Elkins-Tanton", "given": "L. T." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Fassett-C-I", "name": { "family": "Fassett", "given": "C. I." }, "orcid": "0000-0001-9155-3804" }, { "id": "Fischer-W-W", "name": { "family": "Fischer", "given": "W. W." }, "orcid": "0000-0002-8836-3054" }, { "id": "Fraeman-A-A", "name": { "family": "Fraeman", "given": "A. A." }, "orcid": "0000-0003-4017-5158" }, { "id": "Golombek-M-P", "name": { "family": "Golombek", "given": "M. P." }, "orcid": "0000-0002-1928-2293" }, { "id": "Hamilton-V-E", "name": { "family": "Hamilton", "given": "V. E." }, "orcid": "0000-0001-8675-2083" }, { "id": "Hayes-A-G", "name": { "family": "Hayes", "given": "A. G." } }, { "id": "Herd-C-D-K", "name": { "family": "Herd", "given": "C. D. K." } }, { "id": "Horgan-B-H", "name": { "family": "Horgan", "given": "B." } }, { "id": "Hu-R", "name": { "family": "Hu", "given": "R." } }, { "id": "Jakosky-B-M", "name": { "family": "Jakosky", "given": "B. M." } }, { "id": "Johnson-J-R", "name": { "family": "Johnson", "given": "J. R." }, "orcid": "0000-0002-5586-4901" }, { "id": "Kasting-J-F", "name": { "family": "Kasting", "given": "J. F." }, "orcid": "0000-0003-4042-2067" }, { "id": "Kerber-L", "name": { "family": "Kerber", "given": "L." } }, { "id": "Kinch-K-M", "name": { "family": "Kinch", "given": "K. M." }, "orcid": "0000-0002-4629-8880" }, { "id": "Kite-E-S", "name": { "family": "Kite", "given": "E. S." }, "orcid": "0000-0002-1426-1186" }, { "id": "Knutson-H-A", "name": { "family": "Knutson", "given": "H. A." }, "orcid": "0000-0002-5375-4725" }, { "id": "Lunine-J-I", "name": { "family": "Lunine", "given": "J. I." }, "orcid": "0000-0003-2279-4131" }, { "id": "Mahaffy-P-R", "name": { "family": "Mahaffy", "given": "P. R." }, "orcid": "0000-0003-1896-1726" }, { "id": "Mangold-N", "name": { "family": "Mangold", "given": "N." }, "orcid": "0000-0002-0022-0631" }, { "id": "McCubbin-F-M", "name": { "family": "McCubbin", "given": "F. M." } }, { "id": "Mustard-J-F", "name": { "family": "Mustard", "given": "J. F." } }, { "id": "Niles-P-B", "name": { "family": "Niles", "given": "P. B." } }, { "id": "Quantin-Nataf-C", "name": { "family": "Quantin-Nataf", "given": "C." } }, { "id": "Rice-M-S", "name": { "family": "Rice", "given": "M. S." }, "orcid": "0000-0002-8370-4139" }, { "id": "Stack-K-M", "name": { "family": "Stack", "given": "K. M." }, "orcid": "0000-0003-3444-6695" }, { "id": "Stevenson-D-J", "name": { "family": "Stevenson", "given": "D. J." }, "orcid": "0000-0001-9432-7159" }, { "id": "Stewart-S-T", "name": { "family": "Stewart", "given": "S. T." } }, { "id": "Toplis-M-J", "name": { "family": "Toplis", "given": "M. J." } }, { "id": "Usui-T", "name": { "family": "Usui", "given": "T." } }, { "id": "Weiss-B-P", "name": { "family": "Weiss", "given": "B. P." } }, { "id": "Werner-S-C", "name": { "family": "Werner", "given": "S. C." } }, { "id": "Wordsworth-R-D", "name": { "family": "Wordsworth", "given": "R. D." }, "orcid": "0000-0003-1127-8334" }, { "id": "Wray-J-J", "name": { "family": "Wray", "given": "J. J." } }, { "id": "Yingst-R-A", "name": { "family": "Yingst", "given": "R. A." }, "orcid": "0000-0002-0628-4265" }, { "id": "Yung-Y-L", "name": { "family": "Yung", "given": "Y. L." }, "orcid": "0000-0002-4263-2562" }, { "id": "Zahnle-K-J", "name": { "family": "Zahnle", "given": "K. J." } } ] }, "title": "The Sustainability of Habitability on Terrestrial Planets: Insights, Questions, and Needed Measurements from Mars for Understanding the Evolution of Earth-like Worlds", "ispublished": "pub", "full_text_status": "public", "keywords": "Mars history; Planetary evolution; Habitability; Sustainability; Terrestrial exoplanets", "note": "\u00a9 2016 American Geophysical Union. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. \n\nAccepted manuscript online: 15 September 2016; Manuscript Accepted: 13 September 2016; Manuscript Revised: 12 September 2016; Manuscript Received: 16 July 2016. \n\nOne of us (Y.L.Y.) thanks Vlada Stamenkovic for illuminating discussions of the Martian atmosphere at the KISS Workshop on Methane on Mars. As per AGU's data availability policy, this paper is a review paper and contains no new data. Thanks to two reviewers and the editor for comments that improved this manuscript.\n\nPublished - Ehlmann_et_al-2016-Journal_of_Geophysical_Research-_Planets.pdf
", "abstract": "What allows a planet to be both within a potentially habitable zone and sustain habitability over long geologic time? With the advent of exoplanetary astronomy and the ongoing discovery of terrestrial-type planets around other stars, our own solar system becomes a key testing ground for ideas about what factors control planetary evolution. Mars provides the solar system's longest record of the interplay of the physical and chemical processes relevant to habitability on an accessible rocky planet with an atmosphere and hydrosphere. Here we review current understanding and update the timeline of key processes in early Mars history. We then draw on knowledge of exoplanets and the other solar system terrestrial planets to identify six broad questions of high importance to the development and sustaining of habitability (unprioritized): (1) Is small planetary size fatal? (2) How do magnetic fields influence atmospheric evolution? (3) To what extent does starting composition dictate subsequent evolution, including redox processes and the availability of water and organics? (4) Does early impact bombardment have a net deleterious or beneficial influence? (5) How do planetary climates respond to stellar evolution, e.g., sustaining early liquid water in spite of a faint young Sun? (6) How important are the timescales of climate forcing and their dynamical drivers? Finally, we suggest crucial types of Mars measurements (unprioritized) to address these questions: (1) in situ petrology at multiple units/sites; (2) continued quantification of volatile reservoirs and new isotopic measurements of H, C, N, O, S, Cl, and noble gases in rocks that sample multiple stratigraphic sections; (3) radiometric age dating of units in stratigraphic sections and from key volcanic and impact units; (4) higher-resolution measurements of heat flux, subsurface structure, and magnetic field anomalies coupled with absolute age dating. Understanding the evolution of early Mars will feed forward to understanding the factors driving the divergent evolutionary paths of the Earth, Venus, and thousands of small rocky extrasolar planets yet to be discovered.", "date": "2016-10", "date_type": "published", "publication": "Journal of Geophysical Research. Planets", "volume": "121", "number": "10", "publisher": "American Geophysical Union", "pagerange": "1927-1961", "id_number": "CaltechAUTHORS:20160916-124841566", "issn": "2169-9097", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160916-124841566", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/2016JE005134", "primary_object": { "basename": "Ehlmann_et_al-2016-Journal_of_Geophysical_Research-_Planets.pdf", "url": "https://authors.library.caltech.edu/records/jp6c1-n2g81/files/Ehlmann_et_al-2016-Journal_of_Geophysical_Research-_Planets.pdf" }, "resource_type": "article", "pub_year": "2016", "author_list": "Ehlmann, B. L.; Anderson, F. S.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ahbaj-qjs88", "eprint_id": 69010, "eprint_status": "archive", "datestamp": "2023-08-22 18:22:18", "lastmod": "2023-10-20 16:26:01", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Cooper-F-J", "name": { "family": "Cooper", "given": "F. J." } }, { "id": "Adams-B-A", "name": { "family": "Adams", "given": "B. A." } }, { "id": "Blundy-J-D", "name": { "family": "Blundy", "given": "J. D." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "McKeon-R-E", "name": { "family": "McKeon", "given": "R. E." } }, { "id": "Ruggiero-A", "name": { "family": "Ruggiero", "given": "A." } } ] }, "title": "Aridity-induced Miocene canyon incision in the Central Andes", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2016 Geological Society of America. \n\nManuscript received 5 January 2016; Revised manuscript received 19 June 2016; Manuscript accepted 23 June 2016; First published on July 12, 2016. \n\nThis work was funded by BHP Billiton. We are grateful to Jean des Rivi\u00e8res for granting access to the drill core, the geologists at Cerro Colorado mine for assistance with sampling, Donny Hutton for logistical support in Chile, and Lindsey Hedges for help with the laboratory analyses. We thank Matthew Rossi for comments on an earlier version of the manuscript; Simon Lamb, Matthew Jungers, and an anonymous reviewer for their detailed and helpful reviews; and Jim Spotila for editorial handling.", "abstract": "The relationship between the rise of the Andean mountain chain and the onset of aridity on its western margin is poorly understood. Canyon incision on both the eastern and western flanks of the chain is interpreted generally as a direct response to increased rock uplift, but may equally have been the result of climate change. Here we record some of the oldest canyon incision on the western Andean margin by tracking the downward migration of the local water table using (U-Th)/He hematite geochronology on vertical drill-core transects. Our data constrain the incision history of the Quebrada de Parca canyon in northern Chile from ca. 16 Ma to the present day. The erosional and topographic response of the Quebrada de Parca river suggests that incision was induced by a switch to a more arid climate in the middle Miocene, which reduced regional precipitation and river discharge. Geomorphic analysis of the modern river suggests that the Central Andes have gained only \u223c700 m of elevation since incision began, and had therefore reached at least 50% of their current elevation by middle Miocene time. We thus conclude that the onset of aridity at ca. 16 Ma occurred subsequent to the main Andean uplift.", "date": "2016-08", "date_type": "published", "publication": "Geology", "volume": "44", "number": "8", "publisher": "Geological Society of America", "pagerange": "675-678", "id_number": "CaltechAUTHORS:20160713-140128252", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-140128252", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "BHP Billiton" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/G38254.1", "resource_type": "article", "pub_year": "2016", "author_list": "Cooper, F. J.; Adams, B. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/sg07t-hn406", "eprint_id": 67436, "eprint_status": "archive", "datestamp": "2023-08-22 17:56:30", "lastmod": "2023-10-18 21:11:19", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flowers-R-M", "name": { "family": "Flowers", "given": "Rebecca M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Ketcham-R-A", "name": { "family": "Ketcham", "given": "Richard A." } } ] }, "title": "Response to comment on \"A reporting protocol for thermochronologic modeling illustrated with data from the Grand Canyon\"", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2016 Elsevier B.V. \n\nReceived 5 February 2015, Accepted 10 February 2016, Available online 9 March 2016.", "abstract": "We suggested a reporting protocol for thermochronologic modeling with which to arrange and explain the choice of thermal history modeling inputs, and emphasized the need to fully depict model outputs (Flowers et al., 2015). Our goals were to improve transparency and reproducibility in thermochronologic data interpretation and motivate a broader discussion of this topic. We welcome the contribution by Gallagher (2016), and agree that clearly conveying how well a preferred thermal history model outcome honors the data is essential to allow evaluation of the derived conclusions and how they can be tested. However, in our view, how this goal is best achieved depends largely on the modeling approach. Rather than posing a one-size-fits-all scheme, in this case we suggest that the developers of the modeling software and their user communities should define \"best practices\" to which users should adhere.", "date": "2016-05-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "441", "publisher": "Elsevier", "pagerange": "213", "id_number": "CaltechAUTHORS:20160527-101035029", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160527-101035029", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2016.02.024", "resource_type": "article", "pub_year": "2016", "author_list": "Flowers, Rebecca M.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/1zwgb-2k432", "eprint_id": 64305, "eprint_status": "archive", "datestamp": "2023-08-22 17:43:27", "lastmod": "2023-10-17 20:49:34", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sousa-F-J", "name": { "family": "Sousa", "given": "Francis J." }, "orcid": "0000-0003-1623-4023" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Saleeby-J-B", "name": { "family": "Saleeby", "given": "Jason" } }, { "id": "Clark-M-K", "name": { "family": "Clark", "given": "Marin" }, "orcid": "0000-0002-6141-8422" } ] }, "title": "Eocene activity on the Western Sierra Fault System and its role incising Kings Canyon, California", "ispublished": "pub", "full_text_status": "public", "keywords": "apatite 4He/3He thermochronometry; Sierra Nevada tectonics; Kings River canyon incision; Bayesian Monte Carlo Markov Chain modeling", "note": "\u00a9 2016 Elsevier B.V. \n\nReceived 3 November 2015, Revised 16 January 2016, Accepted 18 January 2016, Available online 1 February 2016. \n\nWe thank Kerry Gallagher for assistance with setting up QTQt runs, Lindsey Hedges for the help with sample preparation, and David Shuster and an anonymous reviewer for helpful comments. This work was supported by National Science Foundation Grant EAR-0408526 to KAF.\n\nSupplemental Material - mmc1.docx
", "abstract": "Combining new and published apatite (U\u2013Th)/He and apatite ^4He/^3He data from along the Kings River canyon, California we rediscover a west-down normal fault on the western slope of the southern Sierra Nevada, one of a series of scarps initially described by Hake (1928) which we call the Western Sierra Fault System. Integrating field observations with apatite (U\u2013Th)/He data, we infer a single fault trace 30 km long, and constrain the vertical offset across this fault to be roughly a kilometer. Thermal modeling of apatite ^4He/^3He data documents a pulse of footwall cooling near the fault and upstream in the footwall at circa 45\u201340 Ma, which we infer to be the timing of a kilometer-scale incision pulse resulting from the fault activity. In the context of published data from the subsurface of the Sacramento and San Joaquin Valleys, our data from the Western Sierra Fault System suggests an Eocene tectonic regime dominated by low-to-moderate magnitude extension, surface uplift, and internal structural deformation of the southern Sierra Nevada and proximal Great Valley forearc.", "date": "2016-04-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "439", "publisher": "Elsevier", "pagerange": "29-38", "id_number": "CaltechAUTHORS:20160208-135123236", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160208-135123236", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0408526" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2016.01.020", "primary_object": { "basename": "mmc1.docx", "url": "https://authors.library.caltech.edu/records/1zwgb-2k432/files/mmc1.docx" }, "resource_type": "article", "pub_year": "2016", "author_list": "Sousa, Francis J.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/g3f6m-n7f85", "eprint_id": 64489, "eprint_status": "archive", "datestamp": "2023-08-22 17:35:49", "lastmod": "2023-10-17 21:26:41", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Martin-P", "name": { "family": "Martin", "given": "P." } }, { "id": "Archer-P-D", "name": { "family": "Archer", "given": "P. D." } }, { "id": "Atreya-S-K", "name": { "family": "Atreya", "given": "S. K." }, "orcid": "0000-0002-1972-1815" }, { "id": "Conrad-P-G", "name": { "family": "Conrad", "given": "P. G." } }, { "id": "Eigenbrode-J-L", "name": { "family": "Eigenbrode", "given": "J. L." }, "orcid": "0000-0003-3089-1986" }, { "id": "Fair\u00e9n-A-G", "name": { "family": "Fair\u00e9n", "given": "A. G." } }, { "id": "Franz-H-B", "name": { "family": "Franz", "given": "H. B." } }, { "id": "Freissinet-C", "name": { "family": "Freissinet", "given": "C." } }, { "id": "Glavin-D-P", "name": { "family": "Glavin", "given": "D. P." }, "orcid": "0000-0001-7779-7765" }, { "id": "Mahaffy-P-R", "name": { "family": "Mahaffy", "given": "P. R." }, "orcid": "0000-0003-1896-1726" }, { "id": "Malespin-C-A", "name": { "family": "Malespin", "given": "C." }, "orcid": "0000-0002-5852-5016" }, { "id": "Ming-Douglas-W", "name": { "family": "Ming", "given": "D. W." }, "orcid": "0000-0003-0567-8876" }, { "id": "Navarro-Gonz\u00e1lez-R", "name": { "family": "Navarro-Gonz\u00e1lez", "given": "R." } }, { "id": "Sutter-B", "name": { "family": "Sutter", "given": "B." }, "orcid": "0000-0002-3036-170X" } ] }, "title": "Light and variable ^(37)Cl/^(35)Cl ratios in rocks from Gale Crater, Mars: Possible signature of perchlorate", "ispublished": "pub", "full_text_status": "public", "keywords": "Mars; Cl isotopes; perchlorate; evolved gas analysis", "note": "\u00a9 2015 Elsevier B.V. \n\nReceived 8 August 2015; Received in revised form 13 December 2015; Accepted 16 December 2015; Available online 22 January 2016. \n\nThis work was supported by the National Aeronautics and Space Administration. This work benefited from several anonymous re-views.\n\nSupplemental Material - mmc1.docx
Supplemental Material - mmc2.pdf
", "abstract": "Cl isotope ratios measured on HCl thermally evolved from as-yet-unknown phases in sedimentary rocks and sand in Gale Crater provide unexpected insights to the Martian surficial Cl cycle. The seven samples yield \u03b4^(37)Cl values ranging from \u22121\u00b125\u2030 to \u221251\u00b15\u2030. Five analyses from two samples of the Sheepbed mudstone (Yellowknife Bay study area) are analytically indistinguishable with a mean \u03b4^(37)Cl of \u221211\u00b17\u2030 (1\u03c3). In contrast, four mudstones/sandstones from the Kimberley and Pahrump study areas also yielded indistinguishable ratios, but with a mean \u03b4^(37)Cl of \u221243\u00b16\u2030. The Rocknest sand deposit gave a highly uncertain \u03b4^(37)Cl value of \u22127\u00b144\u2030.\nThese light and highly variable \u03b4^(37)Cl values are unique among known solar system materials. Two endmember models are offered to account for these observations, and in both, perchlorate, with its extreme ability to fractionate Cl isotopes, is critical. In the first model, SAM is detecting HCl from an oxychlorine compound (e.g., perchlorate) produced from volcanic gas emissions by atmospheric chemical reactions. Similar reactions in Earth's atmosphere may be responsible for the isotopically lightest known Cl outside of this study, in perchlorate from the Atacama Desert. Some of the Gale Crater \u03b4^(37)Cl values are more negative than those in Atacama perchlorate, but because reaction mechanisms and associated fractionation factors are unknown, it is impossible to assess whether this difference is prohibitive. If the negative \u03b4^(37)Cl signal is produced in this fashion, the isotopic variability among samples could arise either from variations in the relative size of the reactant chloride and product perchlorate reservoirs, or from variations in the fraction of perchlorate reduced back to chloride after deposition. Such reduction strongly enriches ^(37)Cl in the residual perchlorate.\nPerchlorate reduction alone offers an alternative endmember model that can explain the observed data if SAM measured HCl derived from chloride. In this model isotopically normal perchlorate produced by an unspecified mechanism is reduced to chloride. Depending on the relative size of the reduced reservoir, the integrated product chloride can vary in isotopic composition from \u221270\u2030 in the first increment all the way to the starting composition if the perchlorate is fully reduced. Thus, variable degrees of perchlorate reduction can produce chloride with the appropriate \u03b4^(37)Cl range. Combination of the two endmember models, in which the perchlorate subject to post-deposition reduction is isotopically negative from atmospheric reactions, is also possible.\nDetermination of the phase hosting the Cl measured by SAM, an oxychlorine compound or chloride, is critical for selecting between these models, and for developing implications of the results for the Mars surficial Cl cycle. At present it is not possible to conclusively establish which phase is responsible (possibly both), but limited evidence favors the conclusion that the measured Cl derives mostly from an oxychlorine compound.", "date": "2016-03-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "438", "publisher": "Elsevier", "pagerange": "14-24", "id_number": "CaltechAUTHORS:20160216-085105769", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160216-085105769", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2015.12.013", "primary_object": { "basename": "mmc1.docx", "url": "https://authors.library.caltech.edu/records/g3f6m-n7f85/files/mmc1.docx" }, "related_objects": [ { "basename": "mmc2.pdf", "url": "https://authors.library.caltech.edu/records/g3f6m-n7f85/files/mmc2.pdf" } ], "resource_type": "article", "pub_year": "2016", "author_list": "Farley, K. A.; Martin, P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/cy89q-zng05", "eprint_id": 64925, "eprint_status": "archive", "datestamp": "2023-08-19 13:03:17", "lastmod": "2023-10-17 21:59:11", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hurowitz-J-A", "name": { "family": "Hurowitz", "given": "J. A." }, "orcid": "0000-0002-5857-8652" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Jacobson-N-S", "name": { "family": "Jacobson", "given": "N. S." } }, { "id": "Asimow-P-D", "name": { "family": "Asimow", "given": "P. D." }, "orcid": "0000-0001-6025-8925" }, { "id": "Cartwright-J-A", "name": { "family": "Cartwright", "given": "J. A." } }, { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "John M." } }, { "id": "Rossman-G-R", "name": { "family": "Rossman", "given": "G. R." }, "orcid": "0000-0002-4571-6884" }, { "id": "Waltenberg-K", "name": { "family": "Waltenberg", "given": "Kathryn" } } ] }, "title": "A New Approach to In-situ K-Ar Geochronology", "ispublished": "unpub", "full_text_status": "public", "note": "Published - a-new-approach-to-in-situ.pdf
", "abstract": "The development of an in-situ geochronology capability for Mars and other planetary surfaces has the potential to fundamentally change our understanding of the evolution of terrestrial bodies in the Solar System. For Mars specifically, many of our most basic scientific questions about the geologic history of the planet require knowledge of the absolute time at which an event or process took place on its surface. For instance, what was the age and rate of early Martian climate change recorded in the mineralogy and morphology of surface lithologies (e.g., [1])? In-situ ages from a few select locations within the globally established stratigraphy of Mars would be transformative, enabling us to place direct chronologic constraints on the timing and rates of impact, volcanic, sedimentary, and aqueous processes on the Martian surface.", "date": "2016-03-02", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20160301-140249059", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160301-140249059", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Keck-Institute-for-Space-Studies" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "a-new-approach-to-in-situ.pdf", "url": "https://authors.library.caltech.edu/records/cy89q-zng05/files/a-new-approach-to-in-situ.pdf" }, "resource_type": "conference_item", "pub_year": "2016", "author_list": "Hurowitz, J. A.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/yxnkv-v3y42", "eprint_id": 64290, "eprint_status": "archive", "datestamp": "2023-08-22 17:16:51", "lastmod": "2023-10-17 19:39:30", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lund-D-C", "name": { "family": "Lund", "given": "D. C." }, "orcid": "0000-0002-4847-2889" }, { "id": "Asimow-P-D", "name": { "family": "Asimow", "given": "P. D." }, "orcid": "0000-0001-6025-8925" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Rooney-T-O", "name": { "family": "Rooney", "given": "T. O." } }, { "id": "Seeley-E", "name": { "family": "Seeley", "given": "E." } }, { "id": "Jackson-E-W", "name": { "family": "Jackson", "given": "E. W." } }, { "id": "Durham-Z-M", "name": { "family": "Durham", "given": "Z. M." } } ] }, "title": "Enhanced East Pacific Rise hydrothermal activity during the last two glacial terminations", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2016 American Association for the Advancement of Science. \n\n14 September 2015; accepted 6 January 2016. \n\nWe dedicate this paper to J. Dymond, whose 1981 treatise on Nazca plate sediments made this work possible. We are also indebted to the Oregon State University Core Repository for carefully preserving the EPR sediment cores since they were collected in the early 1970s. We are grateful to L. Wingate at the University of Michigan and M. Cote at the University of Connecticut for technical support. This work has benefited from discussions with J. Granger, P. Vlahos, B. Fitzgerald, and M. Lyle. Data presented here are available on the National Oceanic and Atmospheric Administration's Paleoclimatology Data website (www.ncdc.noaa.gov/data-access/paleoclimatology-data). Funding was provided by the University of Michigan and the University of Connecticut.\n\nSupplemental Material - aad4296-Lund-SM-table-S1.xlsx
Supplemental Material - aad4296-Lund-SM-table-S2.xlsx
Supplemental Material - aad4296-Lund-SM-table-S3.xlsx
Supplemental Material - aad4296-Lund-SM-table-S4.xlsx
Supplemental Material - aad4296-Lund-SM-table-S5.xlsx
Supplemental Material - aad4296-Lund-SM.pdf
", "abstract": "Mid-ocean ridge magmatism is driven by seafloor spreading and decompression melting of the upper mantle. Melt production is apparently modulated by glacial-interglacial changes in sea level, raising the possibility that magmatic flux acts as a negative feedback on ice-sheet size. The timing of melt variability is poorly constrained, however, precluding a clear link between ridge magmatism and Pleistocene climate transitions. Here we present well-dated sedimentary records from the East Pacific Rise that show evidence of enhanced hydrothermal activity during the last two glacial terminations. We suggest that glacial maxima and lowering of sea level caused anomalous melting in the upper mantle and that the subsequent magmatic anomalies promoted deglaciation through the release of mantle heat and carbon at mid-ocean ridges.", "date": "2016-01-29", "date_type": "published", "publication": "Science", "volume": "351", "number": "6272", "publisher": "American Association for the Advancement of Science", "pagerange": "478-482", "id_number": "CaltechAUTHORS:20160208-084848239", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160208-084848239", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "University of Michigan" }, { "agency": "University of Connecticut" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.aad4296", "primary_object": { "basename": "aad4296-Lund-SM-table-S3.xlsx", "url": "https://authors.library.caltech.edu/records/yxnkv-v3y42/files/aad4296-Lund-SM-table-S3.xlsx" }, "related_objects": [ { "basename": "aad4296-Lund-SM-table-S4.xlsx", "url": "https://authors.library.caltech.edu/records/yxnkv-v3y42/files/aad4296-Lund-SM-table-S4.xlsx" }, { "basename": "aad4296-Lund-SM-table-S5.xlsx", "url": "https://authors.library.caltech.edu/records/yxnkv-v3y42/files/aad4296-Lund-SM-table-S5.xlsx" }, { "basename": "aad4296-Lund-SM.pdf", "url": "https://authors.library.caltech.edu/records/yxnkv-v3y42/files/aad4296-Lund-SM.pdf" }, { "basename": "aad4296-Lund-SM-table-S1.xlsx", "url": "https://authors.library.caltech.edu/records/yxnkv-v3y42/files/aad4296-Lund-SM-table-S1.xlsx" }, { "basename": "aad4296-Lund-SM-table-S2.xlsx", "url": "https://authors.library.caltech.edu/records/yxnkv-v3y42/files/aad4296-Lund-SM-table-S2.xlsx" } ], "resource_type": "article", "pub_year": "2016", "author_list": "Lund, D. C.; Asimow, P. D.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/09aen-4bb61", "eprint_id": 63454, "eprint_status": "archive", "datestamp": "2023-08-22 17:03:38", "lastmod": "2023-10-25 23:50:05", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flowers-R-M", "name": { "family": "Flowers", "given": "Rebecca M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Ketcham-R-A", "name": { "family": "Ketcham", "given": "Richard A." } } ] }, "title": "A reporting protocol for thermochronologic modeling illustrated with data from the Grand Canyon", "ispublished": "pub", "full_text_status": "restricted", "keywords": "thermochronology; thermal history modeling; (U\u2013Th)/He; fission-track; Grand Canyon; apatite", "note": "\u00a9 2015 Elsevier B.V. \n\nReceived in revised form 29 September 2015; Accepted 30 September 2015; Available online 21 October 2015. \n\nSupported by NSF EAR-1144500 and EAR-1126991. We thank Todd Ehlers and Lon Abbott for insightful comments on the manuscript.", "abstract": "Apatite (U\u2013Th)/He and fission-track dates, as well as ^4He/^3He and fission-track length data, provide rich thermal history information. However, numerous choices and assumptions are required on the long road from raw data and observations to potentially complex geologic interpretations. This paper outlines a conceptual framework for this path, with the aim of promoting a broader understanding of how thermochronologic conclusions are derived. The tiered structure consists of thermal history model inputs at Level 1, thermal history model outputs at Level 2, and geologic interpretations at Level 3. Because inverse thermal history modeling is at the heart of converting thermochronologic data to interpretation, for others to evaluate and reproduce conclusions derived from thermochronologic results it is necessary to publish all data required for modeling, report all model inputs, and clearly and completely depict model outputs. Here we suggest a generalized template for a model input table with which to arrange, report and explain the choice of inputs to thermal history models. Model inputs include the thermochronologic data, additional geologic information, and system- and model-specific parameters. As an example we show how the origin of discrepant thermochronologic interpretations in the Grand Canyon can be better understood by using this disciplined approach.", "date": "2015-12-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "432", "publisher": "Elsevier", "pagerange": "425-435", "id_number": "CaltechAUTHORS:20160107-131302811", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160107-131302811", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1144500" }, { "agency": "NSF", "grant_number": "EAR-1126991" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2015.09.053", "resource_type": "article", "pub_year": "2015", "author_list": "Flowers, Rebecca M.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/7c6se-mm531", "eprint_id": 63088, "eprint_status": "archive", "datestamp": "2023-08-22 16:55:44", "lastmod": "2023-10-25 23:30:25", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "McKeon-R", "name": { "family": "McKeon", "given": "R." } } ] }, "title": "Radiometric dating and temperature history of banded iron formation\u2013associated hematite, Gogebic iron range, Michigan, USA", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2015 Geological Society of America. \n\nManuscript received 22 July 2015; Revised manuscript received 7 October 2015; Manuscript accepted 9 October 2015; First published online November 6, 2015. \n\nWe thank S. Kessler and P. Vasconcelos for helpful suggestions. F. Stuart, W. Cannon, B. Smith, and H. Dalstra provided valuable reviews. This work was supported by National Science Foundation grant EAR-1144500.", "abstract": "Newly developed techniques were used to characterize the age, origin, and temperature history of coarse hematite contained in high-grade iron ore. Three botryoidal specimens from two different mines in the Gogebic iron range near Ironwood, Michigan (USA), yielded (U-Th)/^(21)Ne ages concordant with plateau ^4He/^3He ages. These data reveal that while two of the specimens grew at ca. 772 \u00b1 41 Ma, the third formed 300 m.y. later (453 \u00b1 14 Ma). ^4He/^3He polydomain thermochronometry indicates hematite formation at >80 \u00b0C for the older specimens and \u223c60 \u00b0C for the younger. Fe mobilization and recrystallization in open cavities at 3\u20135 km subsurface has occurred episodically or possibly continuously over hundreds of millions of years despite a quiescent tectonic setting throughout this interval. While the analyzed specimens are distinct from typical Fe ore, their ages along with structural relationships constrain the onset of iron enrichment to between 1060 and 770 Ma. Cooling of \u223c0.5 \u00b0C/m.y. ensued between ca. 800 and ca. 550 Ma, declining to \u223c0.1 \u00b0C/m.y. for the last 550 m.y. These data suggest an erosion rate of \u223c6 m/m.y. and \u223c5 km of total erosion of the Superior Upland province through the Phanerozoic, and limit unroofing associated with Pleistocene glaciation to <1 km.", "date": "2015-12", "date_type": "published", "publication": "Geology", "volume": "43", "number": "12", "publisher": "Geological Society of America", "pagerange": "1083-1086", "id_number": "CaltechAUTHORS:20151221-080305404", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151221-080305404", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1144500" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/G37190.1", "resource_type": "article", "pub_year": "2015", "author_list": "Farley, K. A. and McKeon, R." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/7jrkr-8ae63", "eprint_id": 59955, "eprint_status": "archive", "datestamp": "2023-08-22 16:06:18", "lastmod": "2023-10-23 23:26:09", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Beaty-D-W", "name": { "family": "Beaty", "given": "D. W." } }, { "id": "Hays-L-E", "name": { "family": "Hays", "given": "L. E." } }, { "id": "Williford-K", "name": { "family": "Williford", "given": "K." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Sample Science Input to Landing Site Selection for Mars 2020: An In-Situ Exploration and Sample Caching Rover", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2015 Meteoritical Society.\n\nPublished - Beaty_2015p5340.pdf
", "abstract": "One of the Mars 2020 Rover mission's main objectives is to collect samples of martian material and seal them in individual tubes for possible return by a later mission[1]. In order for the M2020 rover to have the highest chances of making a significant discovery from the diverse kinds of geological targets that Mars offers, it is crucial to select a landing site that would put the rover in proximity to these features. The M2020 landing site selection process is open to all [2]; however at this meeting we are seeking input from the sample science community into attributes of the landing site that should be prioritized. This paper seeks to foster broader intellectual inputs from the community, and outputs from this discussion will be provided to the M2020 landing site selection committee.", "date": "2015-08", "date_type": "published", "publication": "Meteoritics and Planetary Science", "volume": "50", "number": "S1", "publisher": "Meteoritical Society", "pagerange": "Art. No. 5340", "id_number": "CaltechAUTHORS:20150828-111532014", "issn": "1086-9379", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150828-111532014", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/maps.12501", "primary_object": { "basename": "Beaty_2015p5340.pdf", "url": "https://authors.library.caltech.edu/records/7jrkr-8ae63/files/Beaty_2015p5340.pdf" }, "resource_type": "article", "pub_year": "2015", "author_list": "Beaty, D. W.; Hays, L. E.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/p7a77-3tv96", "eprint_id": 58915, "eprint_status": "archive", "datestamp": "2023-08-22 15:49:09", "lastmod": "2023-10-23 19:52:31", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Garapi\u0107-G", "name": { "family": "Garapi\u0107", "given": "G." } }, { "id": "Jackson-Matthew-G", "name": { "family": "Jackson", "given": "M. G." } }, { "id": "Hauri-Erik-H", "name": { "family": "Hauri", "given": "E. H." }, "orcid": "0000-0002-7449-4774" }, { "id": "Hart-Stanley-R", "name": { "family": "Hart", "given": "S. R." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Blusztajn-Jerzy-S", "name": { "family": "Blusztajn", "given": "J. S." }, "orcid": "0000-0002-5475-1948" }, { "id": "Woodhead-J-D", "name": { "family": "Woodhead", "given": "J. D." } } ] }, "title": "A radiogenic isotopic (He-Sr-Nd-Pb-Os) study of lavas from the Pitcairn hotspot: Implications for the origin of EM-1 (enriched mantle 1)", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Pitcairn; EM-1; sediment recycling; crustal recycling; tholeiite; FOZO 3He/4He", "note": "\u00a9 2015 Elsevier B.V.\n\nReceived 16 January 2015;\nAccepted 15 April 2015;\nAvailable online 25 April 2015.\n\nWe acknowledge the seagoing efforts of Peter Stoffers, the chief\nscientist during the 1989 cruise of the FS Sonne, and H. Craig, the chief\nscientist of the Helious Expedition that visited Pitcairn Island in 1989.\nThe authors acknowledge the constructive comments from Al Hofmann\non a prior version of this manuscript. MGJ acknowledges support from\nNSF grants OCE-1153894, EAR-1348082, EAR-1347377 and EAR-\n1145202.", "abstract": "We present new He-Sr-Nd-Pb-Os isotopic compositions and major and trace-element concentrations for ten subaerially-erupted lavas and one seamount lava associated with the Pitcairn hotspot. The most geochemically-enriched lavas at the Pitcairn hotspot have signatures that are consistent with recycled sediments derived from upper continental crust. Pitcairn lavas have elevated Ti, which also supports the presence of a mafic protolith in the Pitcairn mantle. A subset of Pitcairn seamount samples, including the seamount sample presented here, are tholeiitic. Tholeiitic lavas are uncommon at ocean hotspots located far from mid-ocean ridges. Like tholeiites that erupted in Hawaii, the presence of tholeiites in the Pitcairn magmatic suite can be explained by melting a silica-saturated recycled mafic component in the Pitcairn mantle source. We also present the highest ^3He/^4He ratio (12.6 Ra, ratio to atmosphere) from the Pitcairn hotspot. This sample anchors the high ^(206)Pb/^(204)Pb portion of the Pitcairn array and provides evidence for a plume component in the Pitcairn mantle. In contrast, Pitcairn lavas that have the lowest ^(206)Pb/^(204)Pb are the most geochemically enriched, and have the highest ^(87)Sr/^(86)Sr and lowest ^(143)Nd/^(144)Nd in the Pitcairn suite; these EM-1 end-member lavas have MORB-like ^3He/^4He (~ 8 Ra, ratio to atmosphere). Recycled oceanic crust and sediment suggested to be in the Pitcairn EM-1 mantle are expected to have low ^3He/^4He (< 0.1 Ra). Therefore, the higher, MORB-like ^3He/^4He in Pitcairn EM-1 lavas is paradoxical, but might be explained by diffusive exchange of helium, but not the heavy radiogenic isotopes, with the ambient mantle over billion-year timescales.", "date": "2015-07", "date_type": "published", "publication": "Lithos", "volume": "228-229", "publisher": "Elsevier", "pagerange": "1-11", "id_number": "CaltechAUTHORS:20150717-090957442", "issn": "0024-4937", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150717-090957442", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OCE-1153894" }, { "agency": "NSF", "grant_number": "EAR-1348082" }, { "agency": "NSF", "grant_number": "EAR-1347377" }, { "agency": "NSF", "grant_number": "EAR-1145202" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.lithos.2015.04.010", "resource_type": "article", "pub_year": "2015", "author_list": "Garapi\u0107, G.; Jackson, M. G.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/y827g-9zx17", "eprint_id": 56559, "eprint_status": "archive", "datestamp": "2023-08-22 15:10:36", "lastmod": "2023-10-23 15:33:30", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Riffel-S-B", "name": { "family": "Riffel", "given": "Silvana B." } }, { "id": "Vasconcelos-P-M", "name": { "family": "Vasconcelos", "given": "Paulo M." } }, { "id": "Carmo-I-O", "name": { "family": "Carmo", "given": "Isabela O." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Combined ^(40)Ar/^(39)Ar and (U\u2013Th)/He geochronological constraints on long-term landscape evolution of the Second Paran\u00e1 Plateau and its ruiniform surface features, Paran\u00e1, Brazil", "ispublished": "pub", "full_text_status": "public", "keywords": "Weathering geochronology; 40Ar/39Ar; (U\u2013Th)/He; Landscape evolution; Paran\u00e1", "note": "\u00a9 2014 Elsevier B.V. Received 17 January 2014. Received in revised form 15 October 2014. Accepted 23 October 2014.\nAvailable online 18 December 2014.\n\nThe authors are grateful for the financial support from CAPES (PhD scholarship 4862-06-6), and logistic and financial support from PETROBRAS/CENPES for the ^(40)Ar/^(39)Ar analyses. We are also thankful for the environmental license granted for research at Vila Velha Park (IAP no. 183/09). We are also grateful to the geologist Mathieu Moriss (Paradigm Softwares Technologies Inc.) for the support on DEM volume calculation with the GOCAD software. The construction of the UQ-AGES facility was partially funded by ARC Large Grant A39531815.\n\nSupplemental Material - mmc1.xlsx
Supplemental Material - mmc2.xlsx
Supplemental Material - mmc3.kml
", "abstract": "Regional correlation of dated weathered land surfaces provides the necessary constraints to test long-term continental landscape evolution models, but major challenges remain in properly dating these surfaces. The geomorphological province of Second Paran\u00e1 Plateau, Paran\u00e1 State, Brazil, is a high elevation (ca. 800 m) land surface characterized by widely distributed deep saprolites and scattered lateritic profiles (e.g., Vila Velha and Serra das Almas). Prolonged exposure to weathering and erosion has promoted the pseudo-karstic and ruiniform features that are characteristic of this landscape. In this study, ^(40)Ar/^(39)Ar laser incremental heating geochronology on 22 grains of supergene Mn oxyhydroxides from lateritic profiles at Vila Velha yielded results ranging from 17.2 \u00b1 0.7 to 9.1 \u00b1 0.7 Ma. (U\u2013Th)/He geochronology on 28 goethite grains from the same profile yielded results ranging from 36.4 \u00b1 3.6 to 1.0 \u00b1 0.1 Ma, with an age cluster lying within the 17.2 \u00b1 0.7 to 7.9 \u00b1 0.8 Ma interval. (U\u2013Th)/He geochronology on 17 goethite grains from the Serra das Almas lateritic profile, located 20 km from Vila Velha, yield results ranging from 35.1 \u00b1 3.5 to 14.1 \u00b1 1.4 Ma. The combined results for the two sites reveal a common weathering history that started ca. 35 Ma, suggesting that the Second Paran\u00e1 Plateau results from regional fluvial incision and denudation before ~ 35 Ma, followed by a decline in denudation rates and proportionally more intense weathering. Consistent with the laterite profile central ages, weathering was particularly intense during the Miocene (17\u20138 Ma). Denudation intensified after the Pliocene.", "date": "2015-03-15", "date_type": "published", "publication": "Geomorphology", "volume": "233", "publisher": "Elsevier", "pagerange": "52-63", "id_number": "CaltechAUTHORS:20150409-152949063", "issn": "0169-555X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150409-152949063", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior (CAPES)", "grant_number": "4862-06-6" }, { "agency": "PETROBRAS/CENPES" }, { "agency": "Vila Velha Park", "grant_number": "IAP no. 183/09" }, { "agency": "Australian Research Council", "grant_number": "A39531815" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.geomorph.2014.10.041", "primary_object": { "basename": "mmc2.xlsx", "url": "https://authors.library.caltech.edu/records/y827g-9zx17/files/mmc2.xlsx" }, "related_objects": [ { "basename": "mmc3.kml", "url": "https://authors.library.caltech.edu/records/y827g-9zx17/files/mmc3.kml" }, { "basename": "mmc1.xlsx", "url": "https://authors.library.caltech.edu/records/y827g-9zx17/files/mmc1.xlsx" } ], "resource_type": "article", "pub_year": "2015", "author_list": "Riffel, Silvana B.; Vasconcelos, Paulo M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ep1tr-78c91", "eprint_id": 59743, "eprint_status": "archive", "datestamp": "2023-08-22 15:05:34", "lastmod": "2023-10-23 22:40:23", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Darrach-M", "name": { "family": "Darrach", "given": "Murray" } }, { "id": "Madzunkov-S", "name": { "family": "Madzunkov", "given": "Stojan" } }, { "id": "Schaefer-R", "name": { "family": "Schaefer", "given": "Rembrandt" } }, { "id": "Nikolic-D", "name": { "family": "Nikolic", "given": "Dragan" } }, { "id": "Simcic-J", "name": { "family": "Simcic", "given": "Jurij" } }, { "id": "Kidd-R-D", "name": { "family": "Kidd", "given": "Richard" } }, { "id": "Neidholdt-E-L", "name": { "family": "Neidholdt", "given": "Evan" } }, { "id": "Pilinski-M", "name": { "family": "Pilinski", "given": "Marcin" } }, { "id": "Jaramillo-Botero-A", "name": { "family": "Jaramillo-Botero", "given": "Andres" }, "orcid": "0000-0003-2844-0756" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Ken" }, "orcid": "0000-0002-7846-7546" } ] }, "title": "The Mass Analyzer for Real-time Investigation of Neutrals at Europa (MARINE)", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 IEEE.\n\nThis research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.\n\nPublished - 07119017.pdf
", "abstract": "Presented herein is the progress on developing a new mass analyzer for analysis of the exospheres of planets, moons, and primitive bodies, such as found at Europa or Enceladus. Europa, one of Jupiter's four Galilean moons, may have a subsurface ocean plausibly containing the key ingredients for life as well as sources of chemical energy. Clues to the composition and chemical state of Europa's ocean can be found both on Europa's icy surface and in its tenuous atmosphere. Given the high scientific priority of assessing the habitability of Europa's ocean, the Europa Clipper notional payload includes a Neutral Mass Spectrometer whose purpose is to characterize the composition of ejected surface products during a series of flyby investigations. The Mass Analyzer for Real-time Investigation of Neutrals at Europa (MARINE) is capable of measuring the abundances of neutral particle species in Europa's exosphere including H_2O, O_2, CO_2, and SO_2, and determining their number density profiles at per-second sampling rates as a function of altitude above Europa's surface. MARINE will either detect tracers of potential subsurface biological activity in Europa's exosphere, or place upper limits on their surface abundances. It exceeds all requirements for the proposed investigations with margins ranging from 100 to 1000%, while remaining fully compatible with spacecraft accommodation constraints for mass, power, data volume, and field-of-view.", "date": "2015-03", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-13", "id_number": "CaltechAUTHORS:20150818-140226347", "isbn": "978-1-4799-5379-0", "book_title": "2015 IEEE Aerospace Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150818-140226347", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1109/AERO.2015.7119017", "primary_object": { "basename": "07119017.pdf", "url": "https://authors.library.caltech.edu/records/ep1tr-78c91/files/07119017.pdf" }, "resource_type": "book_section", "pub_year": "2015", "author_list": "Darrach, Murray; Madzunkov, Stojan; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/nmgpn-5qd80", "eprint_id": 59147, "eprint_status": "archive", "datestamp": "2023-08-22 14:52:51", "lastmod": "2023-10-23 20:06:53", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Blard-P-H", "name": { "family": "Blard", "given": "P.-H." } }, { "id": "Balco-G", "name": { "family": "Balco", "given": "G." } }, { "id": "Burnard-P-G", "name": { "family": "Burnard", "given": "P. G." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Fenton-C-R", "name": { "family": "Fenton", "given": "C. R." } }, { "id": "Friedrich-R", "name": { "family": "Friedrich", "given": "R." } }, { "id": "Jull-A-J-T", "name": { "family": "Jull", "given": "A. J. T." } }, { "id": "Niedermann-S", "name": { "family": "Niedermann", "given": "S." } }, { "id": "Pik-R", "name": { "family": "Pik", "given": "R." } }, { "id": "Schaefer-J-M", "name": { "family": "Schaefer", "given": "J. M." } }, { "id": "Scott-E-M", "name": { "family": "Scott", "given": "E. M." } }, { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "D. L." } }, { "id": "Stuart-F-M", "name": { "family": "Stuart", "given": "F. M." } }, { "id": "Stute-M", "name": { "family": "Stute", "given": "M." } }, { "id": "Tibari-B", "name": { "family": "Tibari", "given": "B." } }, { "id": "Winckler-G", "name": { "family": "Winckler", "given": "G." }, "orcid": "0000-0001-8718-2684" }, { "id": "Zimmermann-L", "name": { "family": "Zimmermann", "given": "L." } } ] }, "title": "An inter-laboratory comparison of cosmogenic ^3He and radiogenic ^4He in the CRONUS-P pyroxene standard", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Cosmogenic; 3He; Radiogenic; 4He; CRONUS-P; Standard; Calibration", "note": "\u00a9 2014 Elsevier B.V. \n\nReceived 1 February 2014, Revised 27 August 2014, Accepted 28 August 2014, Available online 7 September 2014. \n\nThis work was funded as part of the CRONUS-Earth program by the US National Science Foundation, grant EAR0345150. Pieter Vermeesch and an anonymous reviewer are thanked for their constructive comments that improved the submitted manuscript. This is CRPG contribution 2327. Editorial handling by: Fred Phillips", "abstract": "This study reports an inter-laboratory comparison of the 3He and 4He concentrations measured in the pyroxene material CRONUS-P. This forms part of the CRONUS-Earth and CRONUS-EU programs, which also produced a series of natural reference materials for in situ produced ^(26)Al, ^(10)Be, ^(14)C, ^(21)Ne and ^(36)Cl.\nSix laboratories (GFZ Potsdam, Caltech Pasadena, CRPG Nancy, SUERC Glasgow, BGC Berkeley, Lamont New York) participated in this intercomparison experiment, analyzing between 5 and 22 aliquots each. Intra-laboratory results yield ^3He concentrations that are consistent with the reported analytical uncertainties, which suggests that ^3He is homogeneous within CRONUS-P. The inter-laboratory dataset (66 determinations from the 6 different labs) is characterized by a global weighted mean of (5.02 \u00b1 0.12) \u00d7 10^9 at g^(\u22121) with an overdispersion of 5.6% (2\u03c3). ^4He is characterized by a larger variability than ^3He, and by an inter-lab global weighted mean of (3.60 \u00b1 0.18) \u00d7 10^(13) at g^(\u22121) (2\u03c3) with an overdispersion of 10.4% (2\u03c3).\nThere are, however, some systematic differences between the six laboratories. More precisely, 2 laboratories obtained mean ^3He concentrations that are about 6% higher than the clustered other 4 laboratories. This systematic bias is larger than the analytical uncertainty and not related to the CRONUS-P material (see Schaefer et al., 2015). Reasons for these inter-laboratory offsets are difficult to identify but are discussed below. To improve the precision of cosmogenic ^3He dating, we suggest that future studies presenting cosmogenic 3He results also report the ^3He concentration measured in the CRONUS-P material in the lab(s) used in a given study.", "date": "2015-02", "date_type": "published", "publication": "Quaternary Geochronology", "volume": "26", "number": "S1", "publisher": "Elsevier", "pagerange": "11-19", "id_number": "CaltechAUTHORS:20150803-073343498", "issn": "1871-1014", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150803-073343498", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0345150" } ] }, "other_numbering_system": { "items": [ { "id": "2327", "name": "CRPG" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.quageo.2014.08.004", "resource_type": "article", "pub_year": "2015", "author_list": "Blard, P.-H.; Balco, G.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/95yta-2sj90", "eprint_id": 52526, "eprint_status": "archive", "datestamp": "2023-08-22 14:47:22", "lastmod": "2023-10-18 20:55:54", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Webster-C-R", "name": { "family": "Webster", "given": "Christopher R." } }, { "id": "Mahaffy-P-R", "name": { "family": "Mahaffy", "given": "Paul R." }, "orcid": "0000-0003-1896-1726" }, { "id": "Atreya-S-K", "name": { "family": "Atreya", "given": "Sushil K." }, "orcid": "0000-0002-1972-1815" }, { "id": "Flesch-G-J", "name": { "family": "Flesch", "given": "Gregory J." } }, { "id": "Mischna-M-A", "name": { "family": "Mischna", "given": "Michael A." }, "orcid": "0000-0002-8022-5319" }, { "id": "Meslin-P-Y", "name": { "family": "Meslin", "given": "Pierre-Yves" }, "orcid": "0000-0002-0703-3951" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Conrad-P-G", "name": { "family": "Conrad", "given": "Pamela G." } }, { "id": "Christensen-L-E", "name": { "family": "Christensen", "given": "Lance E." } }, { "id": "Pavlov-A-A", "name": { "family": "Pavlov", "given": "Alexander A." } }, { "id": "Mart\u00edn-Torres-J", "name": { "family": "Mart\u00edn-Torres", "given": "Javier" } }, { "id": "Zorzano-M-P", "name": { "family": "Zorzano", "given": "Mar\u00eda-Paz" } }, { "id": "McConnochie-T-H", "name": { "family": "McConnochie", "given": "Timothy H." } }, { "id": "Owen-T", "name": { "family": "Owen", "given": "Tobias" } }, { "id": "Eigenbrode-J-L", "name": { "family": "Eigenbrode", "given": "Jennifer L." }, "orcid": "0000-0003-3089-1986" }, { "id": "Glavin-D-P", "name": { "family": "Glavin", "given": "Daniel P." }, "orcid": "0000-0001-7779-7765" }, { "id": "Steele-A-D", "name": { "family": "Steele", "given": "Andrew" } }, { "id": "Malespin-C-A", "name": { "family": "Malespin", "given": "Charles A." }, "orcid": "0000-0002-5852-5016" }, { "id": "Archer-P-D-Jr", "name": { "family": "Archer", "given": "P. Douglas Jr." } }, { "id": "Sutter-B", "name": { "family": "Sutter", "given": "Brad" }, "orcid": "0000-0002-3036-170X" }, { "id": "Coll-P", "name": { "family": "Coll", "given": "Patrice" } }, { "id": "Freissinet-C", "name": { "family": "Freissinet", "given": "Caroline" } }, { "id": "McKay-C-P", "name": { "family": "McKay", "given": "Christopher P." } }, { "id": "Moores-J-E", "name": { "family": "Moores", "given": "John E." } }, { "id": "Schwenzer-S-P", "name": { "family": "Schwenzer", "given": "Susanne P." }, "orcid": "0000-0002-9608-0759" }, { "id": "Bridges-J-C", "name": { "family": "Bridges", "given": "John C." }, "orcid": "0000-0002-9579-5779" }, { "id": "Navarro-Gonz\u00e1lez-Rafael", "name": { "family": "Navarro-Gonz\u00e1lez", "given": "Rafael" } }, { "id": "Gellert-R", "name": { "family": "Gellert", "given": "Ralf" }, "orcid": "0000-0001-7928-834X" }, { "id": "Lemmon-M-T", "name": { "family": "Lemmon", "given": "Mark T." } } ] }, "title": "Mars methane detection and variability at Gale crater", "ispublished": "pub", "full_text_status": "public", "keywords": "Mars; Mars Science Laboratory; Curiosity; methane; Gale crater", "note": "Copyright 2014 American Association for the Advancement of Science.\nReceived for publication 24 September 2014. Accepted for publication 5 December 2014. Published Online [Science Express] December 16 2014.\n\nThe research described here was carried out in part at the Jet Propulsion Laboratory. Cal1forn1a Institute of Technology. under a contract with the National Aeronautics and Space Administration (NASA). Data described 1n the paper are further described 1n the Supplementary Materials and have been submitted to NASA's Planetary Data System (PDS) under an arrangement with the Mars Science Laboratory project. Funding is acknowledged for JMT and MPZ from the Spanish Ministry of Economy and Compet1veness, JCB from the United Kingdom Space Agency. and RG from the Canadian Space Agency.\n\nSupplemental Material - Webster.SM.pdf
", "abstract": "Reports of plumes or patches of methane in the Martian atmosphere that vary over monthly timescales have defied explanation to date. From in situ measurements made over a 20-month period by the Tunable Laser Spectrometer (TLS) of the Sample Analysis at Mars (SAM) instrument suite on Curiosity at Gale Crater, we report detection of background levels of atmospheric methane of mean value 0.69 \u00b1 0.25 ppbv at the 95% confidence interval (CI). This abundance is lower than model estimates of ultraviolet (UV) degradation of accreted interplanetary dust particles (IDP's) or carbonaceous chondrite material. Additionally, in four sequential measurements spanning a 60-sol period, we observed elevated levels of methane of 7.2 \u00b1 2.1 (95% CI) ppbv implying that Mars is episodically producing methane from an additional unknown source.", "date": "2015-01-23", "date_type": "published", "publication": "Science", "volume": "347", "number": "6220", "publisher": "American Association for the Advancement of Science", "pagerange": "415-417", "id_number": "CaltechAUTHORS:20141210-083300697", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141210-083300697", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" }, { "agency": "Ministerio de Econom\u00eda, Industria y Competitividad (MINECO)" }, { "agency": "United Kingdom Space Agency (UKSA)" }, { "agency": "Canadian Space Agency (CSA)" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "corp_creators": { "items": [ "MSL Science Team" ] }, "doi": "10.1126/science.1261713", "primary_object": { "basename": "Webster.SM.pdf", "url": "https://authors.library.caltech.edu/records/95yta-2sj90/files/Webster.SM.pdf" }, "resource_type": "article", "pub_year": "2015", "author_list": "Webster, Christopher R.; Mahaffy, Paul R.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/f0z3n-4mw80", "eprint_id": 50098, "eprint_status": "archive", "datestamp": "2023-08-23 22:57:05", "lastmod": "2023-10-17 22:30:48", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Cox-S-E", "name": { "family": "Cox", "given": "Stephen E." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Cherniak-D-J", "name": { "family": "Cherniak", "given": "Daniele J." } } ] }, "title": "Direct measurement of neon production rates by (\u03b1,n) reactions in minerals", "ispublished": "pub", "full_text_status": "public", "keywords": "Noble gas; Geochronometry; Neon; (U-Th)/Ne; Nucleogenic", "note": "\u00a9 2014 Elsevier B. V. Received 2 April 2014, Accepted 27 August 2014, Available online 21 September 2014.\n\nWe thank Don Burnett for extensive discussion about nuclear chemistry and implantation techniques. We also thank C\u00e9cile Gautheron and Samuel Niedermann for their thoughtful signed reviews, as well as an anonymous reviewer for a third review, and we thank Associate Editor Pete Burnard for his attentive handling of the manuscript. This research was supported by the National Science Foundation through grant NSF-EAR-1144500 to KAF and through a Graduate Research Fellowship to SEC.\n\nSupplemental Material - mmc1.zip
", "abstract": "The production of nucleogenic neon from alpha particle capture by ^(18)O and ^(19)F offers a potential chronometer sensitive to temperatures higher than the more widely used (U-Th)/He chronometer. The accuracy depends on the cross sections and the calculated stopping power for alpha particles in the mineral being studied. Published ^(18)O(\u03b1,n)^(21)Ne production rates are in poor agreement and were calculated from contradictory cross sections, and therefore demand experimental verification. Similarly, the stopping powers for alpha particles are calculated from SRIM (Stopping Range of Ions in Matter software) based on a limited experimental dataset. To address these issues we used a particle accelerator to implant alpha particles at precisely known energies into slabs of synthetic quartz (SiO_2) and barium tungstate (BaWO_4) to measure ^(21)Ne production from capture by ^(18)O. Within experimental uncertainties the observed ^(21)Ne production rates compare favorably to our predictions using published cross sections and stopping powers, indicating that ages calculated using these quantities are accurate at the \u223c3% level. In addition, we measured the ^(22)Ne/^(21)Ne ratio and (U-Th)/He and (U-Th)/Ne ages of Durango fluorapatite, which is an important model system for this work because it contains both oxygen and fluorine. Finally, we present ^(21)Ne/^4He production rate ratios for a variety of minerals of geochemical interest along with software for calculating neon production rates and (U-Th)/Ne ages.", "date": "2015-01-01", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "148", "publisher": "Elsevier", "pagerange": "130-144", "id_number": "CaltechAUTHORS:20140929-123551053", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140929-123551053", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1144500" }, { "agency": "NSF Graduate Research Fellowship" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2014.08.036", "primary_object": { "basename": "1-s2.0-S0016703714005419-main.pdf", "url": "https://authors.library.caltech.edu/records/f0z3n-4mw80/files/1-s2.0-S0016703714005419-main.pdf" }, "related_objects": [ { "basename": "mmc1.zip", "url": "https://authors.library.caltech.edu/records/f0z3n-4mw80/files/mmc1.zip" } ], "resource_type": "article", "pub_year": "2015", "author_list": "Cox, Stephen E.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/nj27z-6nf58", "eprint_id": 48716, "eprint_status": "archive", "datestamp": "2023-08-22 13:57:16", "lastmod": "2023-10-17 20:22:27", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jackson-Matthew-G", "name": { "family": "Jackson", "given": "M. G." } }, { "id": "Hart-Stanley-R", "name": { "family": "Hart", "given": "S. R." } }, { "id": "Konter-J-G", "name": { "family": "Konter", "given": "J. G." } }, { "id": "Kurz-Mark-D", "name": { "family": "Kurz", "given": "M. D." }, "orcid": "0000-0003-1745-2356" }, { "id": "Blusztajn-Jerzy-S", "name": { "family": "Blusztajn", "given": "J." }, "orcid": "0000-0002-5475-1948" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Helium and lead isotopes reveal the geochemical geometry of the Samoan plume", "ispublished": "pub", "full_text_status": "public", "keywords": "Geochemistry, Geodynamics, Volcanology", "note": "\u00a92014 Macmillan Publishers Limited.\nReceived 01 February 2014. Accepted 15 August 2014. Published online 15 October 2014.\n\nWe thank J. Natland, P. Hall and M. Regelous for discussions, and R. Carlson for access to analytical facilities. Comments from B. Hanan and K. Harpp improved the manuscript. M.G.J. acknowledges grants from the NSF that funded this research: OCE-1061134, OCE-1153894, EAR-1348082 and EAR-1145202.\n\nOnline Content Methods, along with any additional Extended Data display items and Source Data, are available in the online version of the paper; references unique to these sections appear only in the online paper.\n\nSupplemental Material - nature13794-s1.xls
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Supplemental Material - nature13794-s3.xlsx
Supplemental Material - nature13794-s4.xlsx
", "abstract": "Hotspot lavas erupted at ocean islands exhibit tremendous isotopic variability, indicating that there are numerous mantle components1, 2 hosted in upwelling mantle plumes that generate volcanism at hotspots like Hawaii and Samoa3. However, it is not known how the surface expression of the various geochemical components observed in hotspot volcanoes relates to their spatial distribution within the plume4, 5, 6, 7, 8, 9, 10. Here we present a relationship between He and Pb isotopes in Samoan lavas that places severe constraints on the distribution of geochemical species within the plume. The Pb-isotopic compositions of the Samoan lavas reveal several distinct geochemical groups, each corresponding to a different geographic lineament of volcanoes. Each group has a signature associated with one of four mantle endmembers with low 3He/4He: EMII (enriched mantle 2), EMI (enriched mantle 1), HIMU (high \u00b5 = 238U/204Pb) and DM (depleted mantle). Critically, these four geochemical groups trend towards a common region of Pb-isotopic space with high 3He/4He. This observation is consistent with several low-3He/4He components in the plume mixing with a common high-3He/4He component, but not mixing much with each other. The mixing relationships inferred from the new He and Pb isotopic data provide the clearest picture yet of the geochemical geometry of a mantle plume, and are best explained by a high-3He/4He plume matrix that hosts, and mixes with, several distinct low-3He/4He components.", "date": "2014-10-16", "date_type": "published", "publication": "Nature", "volume": "514", "publisher": "Nature Publishing Group", "pagerange": "355-358", "id_number": "CaltechAUTHORS:20140820-091223045", "issn": "0028-0836", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140820-091223045", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OCE-1061134" }, { "agency": "NSF", "grant_number": "OCE-1153894" }, { "agency": "NSF", "grant_number": "EAR-1348082" }, { "agency": "NSF", "grant_number": "EAR-1145202" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/nature13794", "primary_object": { "basename": "nature13794-s3.xlsx", "url": "https://authors.library.caltech.edu/records/nj27z-6nf58/files/nature13794-s3.xlsx" }, "related_objects": [ { "basename": "nature13794-s4.xlsx", "url": "https://authors.library.caltech.edu/records/nj27z-6nf58/files/nature13794-s4.xlsx" }, { "basename": "nature13794-s1.xls", "url": "https://authors.library.caltech.edu/records/nj27z-6nf58/files/nature13794-s1.xls" }, { "basename": "nature13794-s2.xlsx", "url": "https://authors.library.caltech.edu/records/nj27z-6nf58/files/nature13794-s2.xlsx" } ], "resource_type": "article", "pub_year": "2014", "author_list": "Jackson, M. G.; Hart, S. R.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/y01m9-kd871", "eprint_id": 50028, "eprint_status": "archive", "datestamp": "2023-08-22 13:36:11", "lastmod": "2023-10-17 22:27:17", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bralower-T-J", "name": { "family": "Bralower", "given": "Timothy J." } }, { "id": "Kelly-D-C", "name": { "family": "Kelly", "given": "D. Clay" } }, { "id": "Gibbs-S", "name": { "family": "Gibbs", "given": "Samantha" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth" }, "orcid": "0000-0002-7846-7546" }, { "id": "Eccles-L", "name": { "family": "Eccles", "given": "Laurie" } }, { "id": "Lindemann-T-L", "name": { "family": "Lindemann", "given": "T. Logan" } }, { "id": "Smith-G-J", "name": { "family": "Smith", "given": "Gregory J." } } ] }, "title": "Impact of dissolution on the sedimentary record of the Paleocene\u2013Eocene thermal maximum", "ispublished": "pub", "full_text_status": "public", "keywords": "dissolution; chemical erosion; nannofossils; planktonic foraminifera; Paleocene Eocene thermal maximum", "note": "\u00a9 2014 Elsevier B.V.\n\nReceived 23 October 2013;\nReceived in revised form 10 May 2014;\nAccepted 27 May 2014;\nAvailable online 19 June 2014;\nEditor: G.M. Henderson.\n\nWe thank Jenny Norman of the Mark Wainwright Analytical Centre, University of New South Wales for assistance with electron microscopy. We thank Lee Kump, Andy Ridgwell and Sandra Kirtland Turner for insightful discussions, Thomas Westerhold for stratigraphic information, and Jerry Dickens and two anonymous reviews for very constructive and extremely helpful critique and advice. This research used samples provided by the Integrated Ocean Drilling Program (IODP). Research funded by the National Science Foundation (EAR06-28394) to Bralower and (OCE-1060877C) to Farley.\n\nSupplemental Material - Plate3.png
Supplemental Material - mmc1.docx
Supplemental Material - mmc2.pdf
Supplemental Material - mmc3.pdf
", "abstract": "The input of massive amounts of carbon to the atmosphere and ocean at the Paleocene\u2013Eocene Thermal Maximum (PETM; \u223c55.53 Ma) resulted in pervasive carbonate dissolution at the seafloor. At many sites this dissolution also penetrated into the underlying sediment column. The magnitude of dissolution at and below the seafloor, a process known as chemical erosion, and its effect on the stratigraphy of the PETM, are notoriously difficult to constrain. Here, we illuminate the impact of dissolution by analyzing the complete spectrum of sedimentological grain sizes across the PETM at three deep-sea sites characterized by a range of bottom water dissolution intensity. We show that the grain size spectrum provides a measure of the sediment fraction lost during dissolution. We compare these data with dissolution and other proxy records, electron micrograph observations of samples and lithology. The complete data set indicates that the two sites with slower carbonate accumulation, and less active bioturbation, are characterized by significant chemical erosion. At the third site, higher carbonate accumulation rates, more active bioturbation, and possibly winnowing have limited the impacts of dissolution. However, grain size data suggest that bioturbation and winnowing were not sufficiently intense to diminish the fidelity of isotopic and microfossil assemblage records.", "date": "2014-09-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "401", "publisher": "Elsevier", "pagerange": "70-82", "id_number": "CaltechAUTHORS:20140925-105050473", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140925-105050473", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR06-28394" }, { "agency": "NSF", "grant_number": "OCE-1060877C" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2014.05.055", "primary_object": { "basename": "Plate3.png", "url": "https://authors.library.caltech.edu/records/y01m9-kd871/files/Plate3.png" }, "related_objects": [ { "basename": "mmc1.docx", "url": "https://authors.library.caltech.edu/records/y01m9-kd871/files/mmc1.docx" }, { "basename": "mmc2.pdf", "url": "https://authors.library.caltech.edu/records/y01m9-kd871/files/mmc2.pdf" }, { "basename": "mmc3.pdf", "url": "https://authors.library.caltech.edu/records/y01m9-kd871/files/mmc3.pdf" } ], "resource_type": "article", "pub_year": "2014", "author_list": "Bralower, Timothy J.; Kelly, D. Clay; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/bfjsq-y7h16", "eprint_id": 50060, "eprint_status": "archive", "datestamp": "2023-08-22 13:06:31", "lastmod": "2023-10-17 22:28:49", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mackey-B-H", "name": { "family": "Mackey", "given": "Benjamin H." } }, { "id": "Scheingross-J-S", "name": { "family": "Scheingross", "given": "Joel S." }, "orcid": "0000-0002-7220-8084" }, { "id": "Lamb-M-P", "name": { "family": "Lamb", "given": "Michael P." }, "orcid": "0000-0002-5701-0504" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Knickpoint formation, rapid propagation, and landscape response following coastal cliff retreat at the last interglacial sea-level highstand: Kaua'i, Hawai'i", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2014 Geological Society of America.\n\nReceived 22 May 2013.\nRevision received 19 November 2013.\nAccepted 31 December 2013.\nFirst published online March 6, 2014.\n\nThis study was funded by the National Science\nFoundation (NSF) grants EAR-1204375 and EAR-\n1147381 to Lamb. Light detection and ranging\n(LiDAR ) data were collected by the NSF National\nCenter for Airborne Laser Mapping with a seed grant\nto Mathieu Lapotre. We thank Will Amidon and\nLindsey Hedges for help in processing the cosmogenic\n^3He samples. We had discussions with and\nfield support from Taylor Perron, Ken Ferrier, Sujoy\nMukhopadhyay, Matt Rosener, and Chuck Blay.\nThorough reviews from Ken Ferrier, Kelin Whipple,\nJoel Johnson, an anonymous reviewer, and GSA Bulletin\nassociate editor Anne Jefferson greatly improved\nthis manuscript.", "abstract": "Upstream knickpoint propagation is an important mechanism for channel incision, and it communicates changes in climate, sea level, and tectonics throughout a landscape. Few studies have directly measured the long-term rate of knickpoint retreat, however, and the mechanisms for knickpoint initiation are debated. Here, we use cosmogenic ^3He exposure dating to document the retreat rate of a waterfall in Ka'ula'ula Valley, Kaua'i, Hawai'i, an often-used site for knickpoint-erosion modeling. Cosmogenic exposure ages of abandoned surfaces are oldest near the coast (120 ka) and systematically decrease with upstream distance toward the waterfall (<10 ka), suggesting that the waterfall migrated nearly 4 km over the past 120 k.y. at an average rate of 33 mm/yr. Upstream of the knickpoint, cosmogenic nuclide concentrations in the channel are approximately uniform and indicate steady-state vertical erosion at a rate of \u223c0.03 mm/yr. Field observations and topographic analysis suggest that waterfall retreat is dominated by block toppling, with sediment transport below the waterfall actively occurring by debris flows. Knickpoint initiation was previously attributed to a submarine landslide ca. 4 Ma; however, our dating results, bathymetric analysis, and landscape-evolution modeling support knickpoint generation by wave-induced sea-cliff erosion during the last interglacial sea-level highstand ca. 120\u2013130 ka. We illustrate that knickpoint generation during sea-level highstands, as opposed to the typical case of sea-level fall, is an important relief-generating mechanism on stable or subsiding steep coasts, and likely drives transient pulses of significant sediment flux.", "date": "2014-07", "date_type": "published", "publication": "Geological Society of America Bulletin", "volume": "126", "number": "7-8", "publisher": "Geological Society of America", "pagerange": "925-942", "id_number": "CaltechAUTHORS:20140926-092926280", "issn": "0016-7606", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140926-092926280", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1204375" }, { "agency": "NSF", "grant_number": "EAR-1147381" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/B30930.1", "resource_type": "article", "pub_year": "2014", "author_list": "Mackey, Benjamin H.; Scheingross, Joel S.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/w1735-es781", "eprint_id": 48549, "eprint_status": "archive", "datestamp": "2023-08-22 13:03:11", "lastmod": "2023-10-17 19:26:02", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Blard-P-H", "name": { "family": "Blard", "given": "Pierre-Henri" } }, { "id": "Lav\u00e9-J", "name": { "family": "Lave", "given": "J\u00e9r\u00f4me" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Ramirez-V", "name": { "family": "Ramirez", "given": "Victor" } }, { "id": "Jimenez-N", "name": { "family": "Jimenez", "given": "Nestor" } }, { "id": "Martin-L-C-P", "name": { "family": "Martin", "given": "L\u00e9o C. P." } }, { "id": "Charreau-J", "name": { "family": "Charreau", "given": "Julien" } }, { "id": "Tibari-B", "name": { "family": "Tibari", "given": "Boucha\u0457b" } }, { "id": "Fornari-M", "name": { "family": "Fornari", "given": "Michel" } } ] }, "title": "Progressive glacial retreat in the Southern Altiplano (Uturuncu volcano, 22\u00b0S) between 65 and 14 ka constrained by cosmogenic ^3He dating", "ispublished": "pub", "full_text_status": "public", "keywords": "Altiplano; Uturuncu; Glaciations; Moraines; Cosmogenic 3He; Equilibrium line altitude; Local last glacial maximum; Lake Tauca", "note": "\u00a9 2014 University of Washington. Published by Elsevier Inc. Received 2 July 2013, Available online 20 March 2014. This work was mainly funded by the INSU programs Relief de la\nTerre and EVE-LEFE and by the ANR Jeune Chercheur GALAC project \"ANR-11-JS56-011-01\". We greatly appreciated the logistical support of the IRD of La Paz (Bolivia) during our field trip of September 2006. The SARM technicians and engineers are kindly acknowledged for their high-quality measurements of major and trace elements of rock samples. Two anonymous reviewers and associate editor David Fink made useful comments that allowed us to improve the article. This is CRPG contribution no. 2285.\n\nSupplemental Material - mmc1.doc
", "abstract": "This work presents the first reconstruction of late Pleistocene glacier fluctuations on Uturuncu volcano, in the Southern Tropical Andes. Cosmogenic ^3He dating of glacial landforms provides constraints on ancient glacier position between 65 and 14 ka. Despite important scatter in the exposure ages on the oldest moraines, probably resulting from pre-exposure, these ^3He data constrain the timing of the moraine deposits and subsequent glacier recessions: the Uturuncu glacier may have reached its maximum extent much before the global LGM, maybe as early as 65 ka, with an equilibrium line altitude (ELA) at 5280 m. Then, the glacier remained close to its maximum position, with a main stillstand identified around 40 ka, and another one between 35 and 17 ka, followed by a limited recession at 17 ka. Then, another glacial stillstand is identified upstream during the late glacial period, probably between 16 and 14 ka, with an ELA standing at 5350 m. This stillstand is synchronous with the paleolake Tauca highstand. This result indicates that this regionally wet and cold episode, during the Heinrich 1 event, also impacted the Southern Altiplano. The ELA rose above 5450 m after 14 ka, synchronously with the Bolling\u2013Allerod.", "date": "2014-07", "date_type": "published", "publication": "Quaternary Research", "volume": "82", "number": "1", "publisher": "Elsevier", "pagerange": "209-221", "id_number": "CaltechAUTHORS:20140814-092609399", "issn": "0033-5894", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140814-092609399", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "INSU Program Relief de la Terre" }, { "agency": "EVE-LEFE" }, { "agency": "ANR Jeune Chercheur GALAC", "grant_number": "ANR-11-JS56-011-01" } ] }, "other_numbering_system": { "items": [ { "id": "2285", "name": "CRPG" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.yqres.2014.02.002", "primary_object": { "basename": "mmc1.doc", "url": "https://authors.library.caltech.edu/records/w1735-es781/files/mmc1.doc" }, "resource_type": "article", "pub_year": "2014", "author_list": "Blard, Pierre-Henri; Lave, J\u00e9r\u00f4me; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/wjzd2-av326", "eprint_id": 46146, "eprint_status": "archive", "datestamp": "2023-08-22 12:42:42", "lastmod": "2023-10-26 18:43:09", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bornemann-A", "name": { "family": "Bornemann", "given": "Andr\u00e9" } }, { "id": "Norris-R-D", "name": { "family": "Norris", "given": "Richard D." } }, { "id": "Lyman-J-A", "name": { "family": "Lyman", "given": "Johnnie A." } }, { "id": "D'haenens-S", "name": { "family": "D'haenens", "given": "Simon" } }, { "id": "Groeneveld-J", "name": { "family": "Groeneveld", "given": "Jeroen" }, "orcid": "0000-0002-8382-8019" }, { "id": "R\u00f6hl-U", "name": { "family": "R\u00f6hl", "given": "Ursula" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Speijer-R-P", "name": { "family": "Speijer", "given": "Robert P." } } ] }, "title": "Persistent environmental change after the Paleocene\u2013Eocene Thermal Maximum in the eastern North Atlantic", "ispublished": "pub", "full_text_status": "public", "keywords": "PETM; carbon isotope excursion; paleoclimatology; paleoceanography; isotope geochemistry", "note": "\u00a9 2014 Elsevier B.V. Received 16 July 2013. Received in revised form 4 March 2014. Accepted 10 March 2014. Available online 1 April 2014. Editor: J. Lynch-Stieglitz. This research used samples and data provided by the ODP. The ODP was sponsored by NSF and participating countries under the management of Joint Oceanographic Institutions (JOI). This manuscript benefited from three constructive reviews of Cedric John and two anonymous reviewers. Financial support was provided by the DFG to AB (BO2505/4-1, BO2505/5-1) and UR. RPS and SD were funded by the Research Foundation Flanders (FWO - G.0422.10) and the Research Fund KU Leuven (OT/08/018), and helium isotope analyses were partially supported by NSF grant OCE-1060877 to KAF. This research used data acquired at the XRF Core Scanner Lab at the MARUM \u2013 Center for Marine Environmental Sciences, University of Bremen.\n\nSupplemental Material - mmc2.xlsx
", "abstract": "The Paleocene\u2013Eocene Thermal Maximum (PETM; \u223c56 Ma) is associated with abrupt climate change, carbon cycle perturbation, ocean acidification, as well as biogeographic shifts in marine and terrestrial biota that were largely reversed as the climatic transient waned. We report a clear exception to the behavior of the PETM as a reversing climatic transient in the eastern North Atlantic (Deep-Sea Drilling Project Site 401, Bay of Biscay) where the PETM initiates a greatly prolonged environmental change compared to other places on Earth where records exist. The observed environmental perturbation extended well past the \u03b4^(13)C recovery phase and up to 650 kyr after the PETM onset according to our extraterrestrial ^3He-based age-model. We observe a strong decoupling of planktic foraminiferal \u03b4^(18)O and Mg/Ca values during the PETM \u03b4^(13)C recovery phase, which in combination with results from helium isotopes and clay mineralogy, suggests that the PETM triggered a hydrologic change in western Europe that increased freshwater flux and the delivery of weathering products to the eastern North Atlantic. This state change persisted long after the carbon-cycle perturbation had stopped. We hypothesize that either long-lived continental drainage patterns were altered by enhanced hydrological cycling induced by the PETM, or alternatively that the climate system in the hinterland area of Site 401 was forced into a new climate state that was not easily reversed in the aftermath of the PETM.", "date": "2014-05-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "394", "publisher": "Elsevier", "pagerange": "70-81", "id_number": "CaltechAUTHORS:20140609-102532088", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140609-102532088", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" }, { "agency": "DFG", "grant_number": "BO2505/4-1" }, { "agency": "DFG", "grant_number": "BO2505/5-1" }, { "agency": "Research Foundation Flanders (FWO)", "grant_number": "G.0422.10" }, { "agency": "Research Fund KU Leuven", "grant_number": "OT/08/018" }, { "agency": "NSF", "grant_number": "OCE-1060877" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2014.03.017", "primary_object": { "basename": "mmc2.xlsx", "url": "https://authors.library.caltech.edu/records/wjzd2-av326/files/mmc2.xlsx" }, "resource_type": "article", "pub_year": "2014", "author_list": "Bornemann, Andr\u00e9; Norris, Richard D.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/a0sqs-tqz45", "eprint_id": 45263, "eprint_status": "archive", "datestamp": "2023-08-22 12:30:00", "lastmod": "2023-10-26 17:54:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Monteiro-H-S", "name": { "family": "Monteiro", "given": "Hevelyn S." }, "orcid": "0000-0002-3797-1869" }, { "id": "Vasconcelos-P-M", "name": { "family": "Vasconcelos", "given": "Paulo M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Spier-C-A", "name": { "family": "Spier", "given": "Carlos A." } }, { "id": "Mello-C-L", "name": { "family": "Mello", "given": "Claudio L." } } ] }, "title": "(U\u2013Th)/He geochronology of goethite and the origin\n and evolution of cangas", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2014 Elsevier Ltd.\n\nReceived 5 August 2013; accepted in revised form 28 January 2014; available online 11 February 2014.\n\nWe thank MBR-Vale for logistic support; UQ-CMM staff for\nhelp during microanalysis; and Lindsey Hedges for help with (U\u2013Th)/He analysis. This project was partly funded by MBR-Vale and by UQ-AGES and the Brazilian Research Concil (CNPq), which sponsored Hevelyn Monteiro's master studies. We are greatful to our external reviewers, Pieter Vermeesch, who suggested to use the HelioPlot software for ploting our (U\u2013Th)/He ages in a log(Th/He) vs log(U.He) diagram, and Alexis K. Ault, who provided pertinent suggestions that helped to improve the organization and clarity of the original manuscript.\n\nSupplemental Material - 1-s2.0-S0016703714000805-fx1.jpg
Supplemental Material - mmc1.xls
", "abstract": "(U\u2013Th)/He geochronology of 147 grains of goethite cements extracted from ferruginous duricrusts (cangas) developed on\nbanded iron-formations from the Quadril\u00e1tero Ferr\u00edfero region, Minas Gerais, Brazil, records a history of protracted mineral dissolution\u2013reprecipitation that started at ca. 48.1 \u00b1 4.8 Ma and continues intermittently until the Present. A large majority of the samples (more than 30%) are younger than 2 Ma, revealing active mineral dissolution\u2013reprecipitation in the recent past. Within cangas, goethite cements are younger near the surface and become progressively older towards the bottom of the weathering profile, indicating that iron is more effectively cycled in the parts of the weathering profile more strongly affected\nby biogenic activity. (U\u2013Th)/He geochronology of 14 goethite grains from saprolites in the same profiles yield results ranging from 55.3 \u00b1 5.5 to 25.7 \u00b1 2.6 Ma. For a single weathering profile, goethite cements from cangas are invariably younger than goethite grains from the underlying saprolite, indicating that the duricrust and the saprolite behave as independent and separate systems responding to different environmental controls. Thorium shows conservative behaviour during goethite dissolution\u2013\nreprecipitation, and it is enriched towards the surface of the weathering profile. Uranium, on the other hand, is\npreferentially leached from the surface into the saprolite or out of the weathering profile. Recurrent goethite dissolution\u2013reprecipitation lends great textural complexities to cangas, but it is also responsible for its capacity to reheal when physically disrupted. This self-healing property accounts for canga's role in armoring banded iron-formation landscapes.", "date": "2014-04-15", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "131", "publisher": "Elsevier", "pagerange": "267-289", "id_number": "CaltechAUTHORS:20140429-083213616", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140429-083213616", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "MBR-Vale" }, { "agency": "UQ-AGES" }, { "agency": "Brazilian Research Concil (CNPq)" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "David L." } } ] }, "doi": "10.1016/j.gca.2014.01.036", "primary_object": { "basename": "1-s2.0-S0016703714000805-fx1.jpg", "url": "https://authors.library.caltech.edu/records/a0sqs-tqz45/files/1-s2.0-S0016703714000805-fx1.jpg" }, "related_objects": [ { "basename": "mmc1.xls", "url": "https://authors.library.caltech.edu/records/a0sqs-tqz45/files/mmc1.xls" } ], "resource_type": "article", "pub_year": "2014", "author_list": "Monteiro, Hevelyn S.; Vasconcelos, Paulo M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/41gcd-m9392", "eprint_id": 47967, "eprint_status": "archive", "datestamp": "2023-08-19 23:25:44", "lastmod": "2023-10-26 21:26:28", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Cecil-M-R", "name": { "family": "Cecil", "given": "M. Robinson" } }, { "id": "Saleeby-Z", "name": { "family": "Saleeby", "given": "Z." } }, { "id": "Saleeby-J-B", "name": { "family": "Saleeby", "given": "J." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Pliocene\u2013Quaternary subsidence and exhumation of the southeastern San Joaquin Basin, California, in response to mantle lithosphere removal", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2014 Geological Society of America.\n\nReceived 24 January 2013; Revision received 13 September 2013; Accepted 16 December 2013; Published online 14 January 2014.\n\nWe thank S.A. Reid, J.R. Boles, M. Irskine, Eric\nHierling, and the California State University, Bakersfi\neld, California Well Sample Repository (CWSR) for\nassistance in securing core samples. Joerg Mattner\nprovided sidewall core from the Smoot well, as well\nas useful discussion about the Kern arch. We benefi ted\ngreatly from laboratory assistance by Alan Chapman\nand Lindsey Hedges and from conversations with\nLaetitia Le Pourhiet, Jan Gillspie, S.A. Graham, and\nD.D. Miller. An early version of this manuscript benefi\nted from the critical reviews of Mark Brandon, Craig\nJones, and Rob Negrini. This work was supported by\nNational Science Foundation grant EAR-0606903 to\nJ. Saleeby, and by a grant from the Gordon and Betty\nMoore Foundation. This is contribution 208 of the\nTectonics Observatory at the California Institute of\nTechnology.\n\nSupplemental Material - 882_SuppFile.doc
", "abstract": "Thermomechanical models of mantle lithosphere removal from beneath the southern Sierra Nevada region, California (USA), predict a complex spatiotemporal pattern of vertical surface displacements. We evaluate these models by using (U-Th)/He thermochronometry, together with other paleothermometry estimates, to investigate such topographic transients. We target Tertiary strata from the Kern arch, a crescent-shaped active uplift located in the southeastern San Joaquin Basin, along the western flank of the southern Sierra Nevada. Kern arch stratigraphy provides a unique record of subsidence and exhumation in a sensitive region immediately adjacent to the delaminating mantle lithosphere at depth. Detrital apatite (U-Th)/He ages from Oligocene\u2013Miocene sandstones collected in Kern arch well cores indicate postdepositional heating to temperatures beyond those corresponding with their present burial depths. When integrated with available geologic and stratigraphic constraints, temperature-time modeling of thermochronometric data suggests partial He loss from apatites at temperatures of 70\u201390 \u00b0C, followed by exhumation to present burial temperatures of 35\u201360 \u00b0C since ca. 6 Ma. By constraining the late Cenozoic geothermal gradient to \u223c25 \u00b0C/km, our results imply 1.0\u20131.6 km of rapid (\u223c0.4 mm/yr) subsidence and sedimentation, and then subsequent uplift and exhumation of southeastern San Joaquin Basin strata in latest Miocene\u2013Quaternary time. Stratigraphic and geomorphic relations further constrain the principal burial episode to ca. 2.5 Ma or later, and exhumation to ca. 1 Ma or later. Subtle differences in the maximum temperatures achieved in various wells may reflect differing degrees of tectonic subsidence and sedimentation as a function of growth faulting and distance from the range front. Our results are consistent with estimates of surface subsidence and uplift from Sierran delamination models, which predict a minimum of \u223c0.7 km of tectonic subsidence in regions retaining mantle lithosphere adjacent to the area of delamination, and a minimum of \u223c0.8 km of rock uplift in regions where delamination occurred recently. We attribute the marked pulse of tectonic subsidence in the San Joaquin Basin to viscous coupling between the lower crust and a downwelling mass in the delaminating slab. The ensuing episode of exhumation is interpreted to result from the northwestward peeling back of the slab and the associated replacement of dense lithosphere with buoyant asthenosphere that drove rapid rock and surface uplift.", "date": "2014-02", "date_type": "published", "publication": "Geosphere", "volume": "10", "number": "1", "publisher": "Geological Society of America", "pagerange": "129-147", "id_number": "CaltechAUTHORS:20140805-103825342", "issn": "1553-040X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140805-103825342", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0606903" }, { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "208", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/GES00882.1", "primary_object": { "basename": "882_SuppFile.doc", "url": "https://authors.library.caltech.edu/records/41gcd-m9392/files/882_SuppFile.doc" }, "resource_type": "article", "pub_year": "2014", "author_list": "Cecil, M. Robinson; Saleeby, Z.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/t7x5t-7bg95", "eprint_id": 42658, "eprint_status": "archive", "datestamp": "2023-08-22 11:33:30", "lastmod": "2023-10-25 17:11:36", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Malespin-Charles-A", "name": { "family": "Malespin", "given": "C." }, "orcid": "0000-0002-5852-5016" }, { "id": "Mahaffy-Paul-R", "name": { "family": "Mahaffy", "given": "P." }, "orcid": "0000-0003-1896-1726" }, { "id": "Grotzinger-J-P", "name": { "family": "Grotzinger", "given": "J. P." }, "orcid": "0000-0001-9324-1257" }, { "id": "Vasconcelos-Paulo-M-P", "name": { "family": "Vasconcelos", "given": "P. M." } }, { "id": "Milliken-Ralph-E", "name": { "family": "Milliken", "given": "R. E." }, "orcid": "0000-0003-3240-4918" }, { "id": "Malin-Michael-C", "name": { "family": "Malin", "given": "M." }, "orcid": "0000-0001-6913-5577" }, { "id": "Edgett-Kenneth-S", "name": { "family": "Edgett", "given": "K. S." }, "orcid": "0000-0001-7197-5751" }, { "id": "Pavlov-Alexander-A", "name": { "family": "Pavlov", "given": "A. A." }, "orcid": "0000-0001-8771-1646" }, { "id": "Hurowitz-Joel-A", "name": { "family": "Hurowitz", "given": "J. A." }, "orcid": "0000-0002-5857-8652" }, { "id": "Grant-John-A", "name": { "family": "Grant", "given": "J. A." }, "orcid": "0000-0001-8276-1281" }, { "id": "Miller-H-B", "name": { "family": "Miller", "given": "H. B." } }, { "id": "Arvidson-Raymond-E", "name": { "family": "Arvidson", "given": "R." }, "orcid": "0000-0002-2854-0362" }, { "id": "Beegle-Luther-W", "name": { "family": "Beegle", "given": "L." }, "orcid": "0000-0002-4944-4353" }, { "id": "Calef-Fred-J-III", "name": { "family": "Calef", "given": "F." }, "orcid": "0000-0002-5132-3980" }, { "id": "Conrad-Pamela-G", "name": { "family": "Conrad", "given": "P. G." }, "orcid": "0000-0001-5724-3343" }, { "id": "Dietrich-William-E", "name": { "family": "Dietrich", "given": "W. E." } }, { "id": "Eigenbrode-Jennifer-L", "name": { "family": "Eigenbrode", "given": "J." }, "orcid": "0000-0003-3089-1986" }, { "id": "Gellert-Ralf", "name": { "family": "Gellert", "given": "R." }, "orcid": "0000-0001-7928-834X" }, { "id": "Gupta-S", "name": { "family": "Gupta", "given": "S." } }, { "id": "Hamilton-Victoria-E", "name": { "family": "Hamilton", "given": "V." }, "orcid": "0000-0001-8675-2083" }, { "id": "Hassler-Donald-M", "name": { "family": "Hassler", "given": "D. M." }, "orcid": "0000-0001-8830-1200" }, { "id": "Lewis-Kevin-W", "name": { "family": "Lewis", "given": "K. W." }, "orcid": "0000-0003-3412-803X" }, { "id": "McLennan-Scott-M", "name": { "family": "McLennan", "given": "S. M." }, "orcid": "0000-0003-4259-7178" }, { "id": "Ming-Douglas-W", "name": { "family": "Ming", "given": "D." }, "orcid": "0000-0003-0567-8876" }, { "id": "Navarro-Gonz\u00e1lez-Rafael", "name": { "family": "Navarro-Gonz\u00e1lez", "given": "R." } }, { "id": "Schwenzer-Susanne-Petra", "name": { "family": "Schwenzer", "given": "S. P." }, "orcid": "0000-0002-9608-0759" }, { "id": "Steele-Andrew-D", "name": { "family": "Steele", "given": "A." }, "orcid": "0000-0001-9643-2841" }, { "id": "Stolper-E-M", "name": { "family": "Stolper", "given": "E. M." }, "orcid": "0000-0001-8008-8804" }, { "id": "Sumner-Dawn-Y", "name": { "family": "Sumner", "given": "D. Y." }, "orcid": "0000-0002-7343-2061" }, { "id": "Vaniman-David-T", "name": { "family": "Vaniman", "given": "D." }, "orcid": "0000-0001-7661-2626" }, { "id": "Vasavada-Ashwin-R", "name": { "family": "Vasavada", "given": "A." }, "orcid": "0000-0003-2665-286X" }, { "id": "Williford-Kenneth-H", "name": { "family": "Williford", "given": "K." }, "orcid": "0000-0003-0633-408X" }, { "id": "Wimmer-Schweingruber-Robert-F", "name": { "family": "Wimmer-Schweingruber", "given": "R. F." }, "orcid": "0000-0002-7388-173X" } ] }, "title": "In Situ Radiometric and Exposure Age Dating of the Martian Surface", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Yellowknife Bay; Gale Crater; Mars; Mars Science Laboratory; Curiosity", "note": "Copyright 2013 American Association for the Advancement of Science. \n\nReceived for publication 14 October 2013. Accepted for publication 25 November 2013. Published Online December 9 2013. \n\nThe authors are indebted to the Mars Science Laboratory Project engineering and management teams for their exceptionally skilled and diligent efforts in making the mission as effective as possible and enhancing science operations. We are also grateful to all those MSL team members who participated in tactical and strategic operations. Without the support of both the engineering and science teams, the data presented here could not have been collected. Three anonymous reviewers provided many helpful suggestions. Some of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Data presented in this paper are archived in the Planetary Data System (pds.nasa.gov).", "abstract": "We determined radiogenic and cosmogenic noble gases in a mudstone on the floor of Gale crater. A K-Ar age of 4.21 \u00b1 0.35 Ga represents a mixture of detrital and authigenic components, and confirms the expected antiquity of rocks comprising the crater rim. Cosmic-ray-produced ^3He, ^(21)Ne, and ^(36)Ar yield concordant surface exposure ages of 78 \u00b1 30 Ma. Surface exposure occurred mainly in the present geomorphic setting rather than during primary erosion and transport. Our observations are consistent with mudstone deposition shortly after the Gale impact, or possibly in a later event of rapid erosion and deposition. The mudstone remained buried until recent exposure by wind-driven scarp retreat. Sedimentary rocks exposed by this mechanism may thus offer the best potential for organic biomarker preservation against destruction by cosmic radiation.", "date": "2014-01-24", "date_type": "published", "publication": "Science", "volume": "343", "number": "6169", "publisher": "American Association for the Advancement of Science", "pagerange": "Art. no. 1247166", "id_number": "CaltechAUTHORS:20131122-123336829", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131122-123336829", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "Keck-Institute-for-Space-Studies" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "corp_creators": { "items": [ "MSL Science Team" ] }, "doi": "10.1126/science.1247166", "resource_type": "article", "pub_year": "2014", "author_list": "Farley, K. A.; Malespin, C.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/bsfbq-nxd73", "eprint_id": 42647, "eprint_status": "archive", "datestamp": "2023-08-22 11:32:52", "lastmod": "2023-10-25 16:58:37", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ming-Douglas-W", "name": { "family": "Ming", "given": "D. W." }, "orcid": "0000-0003-0567-8876" }, { "id": "Archer-P-D", "name": { "family": "Archer", "given": "P. D." } }, { "id": "Glavin-D-P", "name": { "family": "Glavin", "given": "D. P." }, "orcid": "0000-0001-7779-7765" }, { "id": "Eigenbrode-J-L", "name": { "family": "Eigenbrode", "given": "J. L." }, "orcid": "0000-0003-3089-1986" }, { "id": "Franz-H-B", "name": { "family": "Franz", "given": "H. B." } }, { "id": "Sutter-B", "name": { "family": "Sutter", "given": "B." }, "orcid": "0000-0002-3036-170X" }, { "id": "Brunner-A-E", "name": { "family": "Brunner", "given": "A. E." } }, { "id": "Stern-J-C", "name": { "family": "Stern", "given": "J. C." }, "orcid": "0000-0002-0162-8807" }, { "id": "Freissinet-C", "name": { "family": "Freissinet", "given": "C." } }, { "id": "McAdam-A-C", "name": { "family": "McAdam", "given": "A. C." } }, { "id": "Mahaffy-P-R", "name": { "family": "Mahaffy", "given": "P. R." }, "orcid": "0000-0003-1896-1726" }, { "id": "Cabane-M", "name": { "family": "Cabane", "given": "M." } }, { "id": "Coll-P", "name": { "family": "Coll", "given": "P." } }, { "id": "Campbell-J-L", "name": { "family": "Campbell", "given": "J. L." } }, { "id": "Atreya-S-K", "name": { "family": "Atreya", "given": "S. K." }, "orcid": "0000-0002-1972-1815" }, { "id": "Niles-P-B", "name": { "family": "Niles", "given": "P. B." } }, { "id": "Bell-J-F-III", "name": { "family": "Bell", "given": "J. F., III" }, "orcid": "0000-0002-2006-4074" }, { "id": "Bish-D-L", "name": { "family": "Bish", "given": "D. L." } }, { "id": "Brinckerhoff-W-B", "name": { "family": "Brinckerhoff", "given": "W. B." } }, { "id": "Buch-A", "name": { "family": "Buch", "given": "A." } }, { "id": "Conrad-P-G", "name": { "family": "Conrad", "given": "P. G." } }, { "id": "Des-Marais-D-J", "name": { "family": "Des Marais", "given": "D. J." } }, { "id": "Ehlmann-B-L", "name": { "family": "Ehlmann", "given": "B. L." }, "orcid": "0000-0002-2745-3240" }, { "id": "Fair\u00e9n-A-G", "name": { "family": "Fair\u00e9n", "given": "A. G." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K." }, "orcid": "0000-0002-7846-7546" }, { "id": "Flesch-G-J", "name": { "family": "Flesch", "given": "G. J." } }, { "id": "Francois-P", "name": { "family": "Francois", "given": "P." } }, { "id": "Gellert-R", "name": { "family": "Gellert", "given": "R." }, "orcid": "0000-0001-7928-834X" }, { "id": "Grant-J-A", "name": { "family": "Grant", "given": "J. A." }, "orcid": "0000-0001-8276-1281" }, { "id": "Grotzinger-J-P", "name": { "family": "Grotzinger", "given": "J. P." }, "orcid": "0000-0001-9324-1257" }, { "id": "Gupta-S", "name": { "family": "Gupta", "given": "S." } }, { "id": "Herkenhoff-K-E", "name": { "family": "Herkenhoff", "given": "K. E." }, "orcid": "0000-0002-3153-6663" }, { "id": "Hurowitz-J-A", "name": { "family": "Hurowitz", "given": "J. A." }, "orcid": "0000-0002-5857-8652" }, { "id": "Leshin-L-A", "name": { "family": "Leshin", "given": "L. A." } }, { "id": "Lewis-K-W", "name": { "family": "Lewis", "given": "K. W." }, "orcid": "0000-0003-3412-803X" }, { "id": "McLennan-S-M", "name": { "family": "McLennan", "given": "S. M." }, "orcid": "0000-0003-4259-7178" }, { "id": "Miller-K-E", "name": { "family": "Miller", "given": "K. E." } }, { "id": "Moersch-J-E", "name": { "family": "Moersch", "given": "J." } }, { "id": "Morris-R-V", "name": { "family": "Morris", "given": "R. V." } }, { "id": "Navarro-Gonz\u00e1lez-R", "name": { "family": "Navarro-Gonz\u00e1lez", "given": "R." } }, { "id": "Pavlov-A-A", "name": { "family": "Pavlov", "given": "A. A." } }, { "id": "Perrett-G-M", "name": { "family": "Perrett", "given": "G. M." } }, { "id": "Pradler-I", "name": { "family": "Pradler", "given": "I." } }, { "id": "Squyres-S-W", "name": { "family": "Squyres", "given": "S. W." } }, { "id": "Summons-R-E", "name": { "family": "Summons", "given": "R. E." }, "orcid": "0000-0002-7144-8537" }, { "id": "Steele-A-D", "name": { "family": "Steele", "given": "A." } }, { "id": "Stolper-E-M", "name": { "family": "Stolper", "given": "E. M." }, "orcid": "0000-0001-8008-8804" }, { "id": "Sumner-D-Y", "name": { "family": "Sumner", "given": "D. Y." }, "orcid": "0000-0002-7343-2061" }, { "id": "Szopa-C", "name": { "family": "Szopa", "given": "C." } }, { "id": "Teinturier-S", "name": { "family": "Teinturier", "given": "S." } }, { "id": "Trainer-M-G", "name": { "family": "Trainer", "given": "M. G." } }, { "id": "Treiman-A-H", "name": { "family": "Treiman", "given": "A. H." }, "orcid": "0000-0002-8073-2839" }, { "id": "Vaniman-D-T", "name": { "family": "Vaniman", "given": "D. T." }, "orcid": "0000-0001-7661-2626" }, { "id": "Vasavada-A-R", "name": { "family": "Vasavada", "given": "A. R." }, "orcid": "0000-0003-2665-286X" }, { "id": "Webster-C-R", "name": { "family": "Webster", "given": "C. R." } }, { "id": "Wray-J-J", "name": { "family": "Wray", "given": "J. J." } }, { "id": "Yingst-R-A", "name": { "family": "Yingst", "given": "R. A." }, "orcid": "0000-0002-0628-4265" } ] }, "title": "Volatile and Organic Compositions of Sedimentary Rocks in Yellowknife Bay, Gale crater, Mars", "ispublished": "pub", "full_text_status": "public", "keywords": "Yellowknife Bay; Gale Crater; Mars; Mars Science Laboratory; Curiosity", "note": "Copyright 2013 American Association for the Advancement of Science. \n\nSubmitted Manuscript: 7 November 2013. Received for publication 28 August 2013. Accepted for publication 12 November 2013. Published Online December 9 2013. \n\nThe authors are indebted to the Mars Science Laboratory Project engineering and management teams for making this mission possible and enhancing science operations. Much of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration (NASA). NASA provided support for the development of SAM. Data from these SAM experiments are archived in the Planetary Data System (pds.nasa.gov). Essential contributions to the successful operation of SAM on Mars and the acquisition of this data were provided by the SAM development, operations, and testbed teams. Development and operation of the SAM and APXS instruments were also supported by funds from the French Space Agency, CNES and the Canadian Space Agency. Work in the UK was funded by the UK Space Agency. B. L. E., J. L. E., K. F., D. P. G., J. E. G, K. E. M., S. M. M., J. M., P. B. N., and R. E. S. acknowledge funding support from the NASA ROSES MSL Participating Scientist Program.\n\nAccepted Version - Ming_et_al_2013_Science_Sheepbed_Volatiles_Accepted.pdf
", "abstract": "H\u2082O, CO\u2082, SO\u2082, O\u2082, H\u2082, H\u2082S, HCl, chlorinated hydrocarbons, NO and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H\u2082O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO\u2082. Concurrent evolution of O\u2082 and chlorinated hydrocarbons suggest the presence of oxychlorine phase(s). Sulfides are likely sources for S-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic C sources may be preserved in the mudstone; however, the C source for the chlorinated hydrocarbons is not definitively of martian origin.", "date": "2014-01-24", "date_type": "published", "publication": "Science", "volume": "343", "number": "6169", "publisher": "American Association for the Advancement of Science", "pagerange": "Art. no. 1245267", "id_number": "CaltechAUTHORS:20131122-100526751", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131122-100526751", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" }, { "agency": "Centre National d'\u00c9tudes Spatiales (CNES)" }, { "agency": "Canadian Space Agency (CSA)" }, { "agency": "United Kingdom Space Agency (UKSA)" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "corp_creators": { "items": [ "MSL Science Team" ] }, "doi": "10.1126/science.1245267", "primary_object": { "basename": "Ming_et_al_2013_Science_Sheepbed_Volatiles_Accepted.pdf", "url": "https://authors.library.caltech.edu/records/bsfbq-nxd73/files/Ming_et_al_2013_Science_Sheepbed_Volatiles_Accepted.pdf" }, "resource_type": "article", "pub_year": "2014", "author_list": "Ming, D. W.; Archer, P. D.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/t7tw4-36912", "eprint_id": 43043, "eprint_status": "archive", "datestamp": "2023-08-22 11:24:11", "lastmod": "2023-10-25 23:13:50", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lamb-M-P", "name": { "family": "Lamb", "given": "Michael P." }, "orcid": "0000-0002-5701-0504" }, { "id": "Mackey-B-H", "name": { "family": "Mackey", "given": "Benjamin H." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Amphitheater-headed canyons formed by megaflooding at Malad Gorge, Idaho", "ispublished": "pub", "full_text_status": "public", "keywords": "megaflood; knickpoint; sapping; waterfall", "note": "\u00a9 2013 National Academy of Sciences.\n\nEdited by Thure E. Cerling, University of Utah, Salt Lake City, UT, and approved November 25, 2013 (received for review June 27, 2013).\nPublished online before print December 16, 2013.\n\nWe thank Joel Scheingross, Mathieu Lapotre, and\nJim McKean for field assistance; Willy Amidon for sample preparation; and\nBill Phillips for regional comparisons and mapping. This work was supported\nby NSF Grant 1147381 and NASA Grant PGG12-0107 to M.P.L. Comments\nfrom two reviewers strengthened the final version of this paper.\n\nAuthor contributions: M.P.L. and B.H.M. designed research; M.P.L. and B.H.M. performed\nresearch; K.A.F. contributed new reagents/analytic tools; M.P.L., B.H.M., and K.A.F. analyzed\ndata; and M.P.L., B.H.M., and K.A.F. wrote the paper.\nThe authors declare no conflict of interest.\nThis article is a PNAS Direct Submission.\n\nPublished - PNAS-2014-Lamb-57-62.pdf
Supplemental Material - pnas.201312251SI.pdf
", "abstract": "Many bedrock canyons on Earth and Mars were eroded by upstream propagating headwalls, and a prominent goal in geomorphology and planetary science is to determine formation processes from canyon morphology. A diagnostic link between process and form remains highly controversial, however, and field investigations that isolate controls on canyon morphology are needed. Here we investigate the origin of Malad Gorge, Idaho, a canyon system cut into basalt with three remarkably distinct heads: two with amphitheater headwalls and the third housing the active Wood River and ending in a 7% grade knickzone. Scoured rims of the headwalls, relict plunge pools, sediment-transport constraints, and cosmogenic (^3He) exposure ages indicate formation of the amphitheater-headed canyons by large-scale flooding \u223c46 ka, coeval with formation of Box Canyon 18 km to the south as well as the eruption of McKinney Butte Basalt, suggesting widespread canyon formation following lava-flow diversion of the paleo-Wood River. Exposure ages within the knickzone-headed canyon indicate progressive upstream younging of strath terraces and a knickzone propagation rate of 2.5 cm/y over at least the past 33 ka. Results point to a potential diagnostic link between vertical amphitheater headwalls in basalt and rapid erosion during megaflooding due to the onset of block toppling, rather than previous interpretations of seepage erosion, with implications for quantifying the early hydrosphere of Mars.", "date": "2014-01-07", "date_type": "published", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "volume": "111", "number": "1", "publisher": "National Academy of Sciences", "pagerange": "57-62", "id_number": "CaltechAUTHORS:20131217-110151949", "issn": "0027-8424", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131217-110151949", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1147381" }, { "agency": "NASA", "grant_number": "PGG12-0107" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1073/pnas.1312251111", "pmcid": "PMC3890896", "primary_object": { "basename": "PNAS-2014-Lamb-57-62.pdf", "url": "https://authors.library.caltech.edu/records/t7tw4-36912/files/PNAS-2014-Lamb-57-62.pdf" }, "related_objects": [ { "basename": "pnas.201312251SI.pdf", "url": "https://authors.library.caltech.edu/records/t7tw4-36912/files/pnas.201312251SI.pdf" } ], "resource_type": "article", "pub_year": "2014", "author_list": "Lamb, Michael P.; Mackey, Benjamin H.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/aw1gz-ct137", "eprint_id": 42376, "eprint_status": "archive", "datestamp": "2023-08-22 10:38:03", "lastmod": "2023-10-25 15:53:10", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Webster-C-R", "name": { "family": "Webster", "given": "Christopher R." } }, { "id": "Mahaffy-P-R", "name": { "family": "Mahaffy", "given": "Paul R." }, "orcid": "0000-0003-1896-1726" }, { "id": "Atreya-S-K", "name": { "family": "Atreya", "given": "Sushil K." }, "orcid": "0000-0002-1972-1815" }, { "id": "Flesch-G-J", "name": { "family": "Flesch", "given": "Gregory J." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Low Upper Limit to Methane Abundance on Mars", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2013 American Association for the Advancement of Science. \n\n8 July 2013; accepted 5 September 2013; Published online 19 September 2013.\n\nThe research described here was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA). Data described in the paper are further described in the supplementary materials and have been submitted to NASA's Planetary Data System under an arrangement with the Mars Science Laboratory project.\n\nSupplemental Material - Webster.SM.pdf
", "abstract": "By analogy with Earth, methane in the Martian atmosphere is a potential signature of ongoing or past biological activity. During the past decade, Earth-based telescopic observations reported \"plumes\" of methane of tens of parts per billion by volume (ppbv), and those from Mars orbit showed localized patches, prompting speculation of sources from subsurface bacteria or nonbiological sources. From in situ measurements made with the Tunable Laser Spectrometer (TLS) on Curiosity using a distinctive spectral pattern specific to methane, we report no detection of atmospheric methane with a measured value of 0.18 \u00b1 0.67 ppbv corresponding to an upper limit of only 1.3 ppbv (95% confidence level), which reduces the probability of current methanogenic microbial activity on Mars and limits the recent contribution from extraplanetary and geologic sources.", "date": "2013-10-18", "date_type": "published", "publication": "Science", "volume": "342", "number": "6156", "publisher": "American Association for the Advancement of Science", "pagerange": "355-357", "id_number": "CaltechAUTHORS:20131112-104640207", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131112-104640207", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "corp_creators": { "items": [ "MSL Science Team" ] }, "doi": "10.1126/science.1242902", "primary_object": { "basename": "Webster.SM.pdf", "url": "https://authors.library.caltech.edu/records/aw1gz-ct137/files/Webster.SM.pdf" }, "resource_type": "article", "pub_year": "2013", "author_list": "Webster, Christopher R.; Mahaffy, Paul R.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3ccas-sr202", "eprint_id": 89633, "eprint_status": "archive", "datestamp": "2023-08-22 10:38:25", "lastmod": "2023-10-18 22:52:56", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jacobson-N-S", "name": { "family": "Jacobson", "given": "N. S." } }, { "id": "Hurowitz-J-A", "name": { "family": "Hurowitz", "given": "J. A." }, "orcid": "0000-0002-5857-8652" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Asimow-P-D", "name": { "family": "Asimow", "given": "P. D." }, "orcid": "0000-0001-6025-8925" }, { "id": "Cartwright-J-A", "name": { "family": "Cartwright", "given": "J. A." } } ] }, "title": "Novel Applications of Knudsen Effusion Mass Spectrometry", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2013 ECS - The Electrochemical Society. \n\nIt is a pleasure to thank Dr. Evan Copland, formerly at NASA GRC, now with CSIRO, Sydney, Australia for his design of the multiple cell flange and many contributions to high temperature mass spectrometry at the Glenn Research Center.", "abstract": "Knudsen effusion mass spectrometry (KEMS) is a valuable and versatile tool in physical chemistry, materials science, and geology. Most of the applications center on thermodynamic measurements. In this paper two novel applications of KEMS are discussed. The first is the determination of K isotope ratios for application to K-Ar dating. The second is the determination of silica thermodynamic activities in silicates via a reducing agent to increase signals without changing the condensed phase composition. This also involves the measurement of vaporization coefficient via a multi-cell KEMS method.", "date": "2013-10-18", "date_type": "published", "publication": "ECS Transactions", "volume": "58", "number": "3", "publisher": "Electrochemical Society", "pagerange": "3-12", "id_number": "CaltechAUTHORS:20180914-100810777", "issn": "1938-6737", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180914-100810777", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1149/05803.0003ecst", "resource_type": "article", "pub_year": "2013", "author_list": "Jacobson, N. S.; Hurowitz, J. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/yzad2-eqn10", "eprint_id": 43127, "eprint_status": "archive", "datestamp": "2023-08-22 10:34:18", "lastmod": "2023-10-25 23:18:06", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yuan-Dao-Yang", "name": { "family": "Yuan", "given": "Dao-Yang" } }, { "id": "Ge-Wei-Peng", "name": { "family": "Ge", "given": "Wei-Peng" } }, { "id": "Chen-Zhen-Wei", "name": { "family": "Chen", "given": "Zhen-Wei" } }, { "id": "Li-Chuan-You", "name": { "family": "Li", "given": "Chuan-You" } }, { "id": "Wang-Zhi-Cai", "name": { "family": "Wang", "given": "Zhi-Cai" } }, { "id": "Zhang-Hui-Ping", "name": { "family": "Zhang", "given": "Hui-Ping" } }, { "id": "Zhang-Pei-Zhen", "name": { "family": "Zhang", "given": "Pei-Zhen" } }, { "id": "Zheng-De-Wen", "name": { "family": "Zheng", "given": "De-Wen" } }, { "id": "Zheng-Wen-Jun", "name": { "family": "Zheng", "given": "Wen-Jun" } }, { "id": "Craddock-W-H", "name": { "family": "Craddock", "given": "William H." }, "orcid": "0000-0002-4181-4735" }, { "id": "Dayem-K-E", "name": { "family": "Dayem", "given": "Katherine E." } }, { "id": "Duvall-A-R", "name": { "family": "Duvall", "given": "Alison R." }, "orcid": "0000-0002-7760-7236" }, { "id": "Hough-B-G", "name": { "family": "Hough", "given": "Brian G." } }, { "id": "Lease-R-O", "name": { "family": "Lease", "given": "Richard O." }, "orcid": "0000-0003-2582-8966" }, { "id": "Champagnac-J-D", "name": { "family": "Champagnac", "given": "Jean-Daniel" }, "orcid": "0000-0003-1963-2465" }, { "id": "Burbank-D-W", "name": { "family": "Burbank", "given": "Douglas W." }, "orcid": "0000-0001-8497-3296" }, { "id": "Clark-M-K", "name": { "family": "Clark", "given": "Marin K." }, "orcid": "0000-0002-6141-8422" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Garzione-C-N", "name": { "family": "Garzione", "given": "Carmala N." } }, { "id": "Kirby-Eric", "name": { "family": "Kirby", "given": "Eric" }, "orcid": "0000-0002-5701-8688" }, { "id": "Molnar-P", "name": { "family": "Molnar", "given": "Peter" } }, { "id": "Roe-G-H", "name": { "family": "Roe", "given": "Gerard H." }, "orcid": "0000-0001-5906-4779" } ] }, "title": "The growth of northeastern Tibet and its relevance to large-scale continental geodynamics: A review of recent studies", "ispublished": "pub", "full_text_status": "public", "keywords": "Tibet; continents; geodynamics", "note": "\u00a9 2013 American Geophysical Union.\n\nReceived 28 March 2013; revised 12 August 2013; accepted 12 September 2013; published 3 October 2013. \n\nWe thank B. C. Burchfiel and P. G. DeCelles for constructive criticism of the manuscript. This research was supported by the National Science Foundation of the United States under grants EAR 0507730, 0506575, and 0549748; by the Public Service Funds for Earthquake Studies (201008003); by the State Key Laboratory of Earthquake Dynamics (LED2008A01); by the National Science Foundation of China under grants 40234040, 40872132, 40372086, and 41030317; and by the Swiss National Science Foundation under grant PBNE2-106764.\n\nPublished - tect20081.pdf
", "abstract": "Recent studies of the northeastern part of the Tibetan Plateau have called attention to two emerging views of how the Tibetan Plateau has grown. First, deformation in northern Tibet began essentially at the time of collision with India, not 10\u201320 Myr later as might be expected if the locus of activity migrated northward as India penetrated the rest of Eurasia. Thus, the north-south dimensions of the Tibetan Plateau were set mainly by differences in lithospheric strength, with strong lithosphere beneath India and the Tarim and Qaidam basins steadily encroaching on one another as the region between them, the present-day Tibetan Plateau, deformed, and its north-south dimension became narrower. Second, abundant evidence calls for acceleration of deformation, including the formation of new faults, in northeastern Tibet since ~15 Ma and a less precisely dated change in orientation of crustal shortening since ~20 Ma. This reorientation of crustal shortening and roughly concurrent outward growth of high terrain, which swings from NNE-SSW in northern Tibet to more NE-SW and even ENE-WSW in the easternmost part of northeastern Tibet, are likely to be, in part, a consequence of crustal thickening within the high Tibetan Plateau reaching a limit, and the locus of continued shortening then migrating to the northeastern and eastern flanks. These changes in rates and orientation also could result from removal of some or all mantle lithosphere and increased gravitational potential energy per unit area and from a weakening of crustal material so that it could flow in response to pressure gradients set by evolving differences in elevation.", "date": "2013-10-03", "date_type": "published", "publication": "Tectonics", "volume": "32", "number": "5", "publisher": "American Geophysical Union", "pagerange": "1358-1370", "id_number": "CaltechAUTHORS:20131220-155301622", "issn": "0278-7407", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131220-155301622", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR 0507730" }, { "agency": "NSF", "grant_number": "EAR 0506575" }, { "agency": "NSF", "grant_number": "EAR 0549748" }, { "agency": "Public Service Funds for Earthquake Studies", "grant_number": "201008003" }, { "agency": "State Key Laboratory of Earthquake Dynamics", "grant_number": "LED2008A01" }, { "agency": "National Science Foundation of China", "grant_number": "40234040" }, { "agency": "National Science Foundation of China", "grant_number": "40872132" }, { "agency": "National Science Foundation of China", "grant_number": "40372086" }, { "agency": "National Science Foundation of China", "grant_number": "41030317" }, { "agency": "Swiss National Science Foundation", "grant_number": "PBNE2-106764" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/tect.20081", "primary_object": { "basename": "tect20081.pdf", "url": "https://authors.library.caltech.edu/records/yzad2-eqn10/files/tect20081.pdf" }, "resource_type": "article", "pub_year": "2013", "author_list": "Yuan, Dao-Yang; Ge, Wei-Peng; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/v3tnh-4w768", "eprint_id": 43126, "eprint_status": "archive", "datestamp": "2023-08-22 10:33:51", "lastmod": "2023-10-25 23:18:03", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Duvall-A-R", "name": { "family": "Duvall", "given": "Alison R." }, "orcid": "0000-0002-7760-7236" }, { "id": "Clark-M-K", "name": { "family": "Clark", "given": "Marin K." }, "orcid": "0000-0002-6141-8422" }, { "id": "Kirby-Eric", "name": { "family": "Kirby", "given": "Eric" }, "orcid": "0000-0002-5701-8688" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Craddock-W-H", "name": { "family": "Craddock", "given": "William H." }, "orcid": "0000-0002-4181-4735" }, { "id": "Li-Chuanyou", "name": { "family": "Li", "given": "Chuanyou" } }, { "id": "Yuan-Dao-Yang", "name": { "family": "Yuan", "given": "Dao-Yang" } } ] }, "title": "Low-temperature thermochronometry along the Kunlun and Haiyuan Faults, NE Tibetan Plateau: Evidence for kinematic change during late-stage orogenesis", "ispublished": "pub", "full_text_status": "public", "keywords": "Tibetan Plateau; Kunlun Fault; Low-temperature thermochronometry; Strike-slip faults", "note": "\u00a9 2013 American Geophysical Union.\n\nReceived 20 January 2013; revised 4 July 2013; accepted 1 August 2013; published 1 October 2013.\n\nThis work was supported by the NSF (grants EAR-0507431, EAR-0507788, EAR-0908711), the National Science Foundation of China (40234040), and by the State Key Laboratory of\nEarthquake Dynamics (LED2008A01). We thank Lindsay Hedges for assistance with sample analyses, and Nathan Harkins, Xuhua Shi, Katherine Dayem, Karen Lease, colleagues at the Lanzhou Institute of Seismology, Pei-Zhen Zhang and colleagues at the State Key Laboratory of Earthquake\nDynamics, Institute of Geology, China Earthquake Administration for help with sample collection and field support. We also thank anonymous reviewers for thorough and instructive feedback that greatly improved the paper. We also acknowledge Nathan Niemi, Douglas Burbank, Zheng\nDewen, and Peter Molnar for constructive dialogue regarding this work.\n\nPublished - tect20072.pdf
Supplemental Material - FigureS1.pdf
Supplemental Material - SupplementaryMaterial.docx
Supplemental Material - TableS1.xlsx
", "abstract": "The Tibetan Plateau is a prime example of a collisional orogen with widespread strike-slip faults whose age and tectonic significance remain controversial. We present new low-temperature thermochronometry to date periods of exhumation associated with Kunlun and Haiyuan faulting, two major strike-slip faults within the northeastern margin of Tibet. Apatite and zircon (U-Th)/He and apatite fission-track ages, which record exhumation from ~2 to 6\u2009km crustal depths, provide minimum bounds on fault timing. Results from Kunlun samples show increased exhumation rates along the western fault segment at circa 12\u20138 Ma with a possible earlier phase of motion from ~30\u201320 Ma, along the central fault segment at circa 20\u201315 Ma, and along the eastern fault segment at circa 8\u20135 Ma. Combined with previous studies, our results suggest that motion along the Haiyuan fault may have occurred as early as ~15 Ma along the western/central fault segment before initiating at least by 10\u20138 Ma along the eastern fault tip. We relate an ~250\u2009km wide zone of transpressional shear to synchronous Kunlun and Haiyuan fault motion and suggest that the present-day configuration of active faults along the northeastern margin of Tibet was likely established since middle Miocene time. We interpret the onset of transpression to relate to the progressive confinement of Tibet against rigid crustal blocks to the north and expansion of crustal thickening to the east during the later stages of orogen development.", "date": "2013-10-01", "date_type": "published", "publication": "Tectonics", "volume": "32", "number": "5", "publisher": "American Geophysical Union", "pagerange": "1190-1211", "id_number": "CaltechAUTHORS:20131220-155208095", "issn": "0278-7407", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131220-155208095", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0507431" }, { "agency": "NSF", "grant_number": "EAR-0507788" }, { "agency": "NSF", "grant_number": "EAR-0908711" }, { "agency": "National Science Foundation of China", "grant_number": "40234040" }, { "agency": "State Key Laboratory of Earthquake Dynamics", "grant_number": "LED2008A01" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/tect.20072", "primary_object": { "basename": "FigureS1.pdf", "url": "https://authors.library.caltech.edu/records/v3tnh-4w768/files/FigureS1.pdf" }, "related_objects": [ { "basename": "SupplementaryMaterial.docx", "url": "https://authors.library.caltech.edu/records/v3tnh-4w768/files/SupplementaryMaterial.docx" }, { "basename": "TableS1.xlsx", "url": "https://authors.library.caltech.edu/records/v3tnh-4w768/files/TableS1.xlsx" }, { "basename": "tect20072.pdf", "url": "https://authors.library.caltech.edu/records/v3tnh-4w768/files/tect20072.pdf" } ], "resource_type": "article", "pub_year": "2013", "author_list": "Duvall, Alison R.; Clark, Marin K.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/1hszg-9gj27", "eprint_id": 41660, "eprint_status": "archive", "datestamp": "2023-08-22 10:21:01", "lastmod": "2023-10-24 23:54:45", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vasconcelos-P-M", "name": { "family": "Vasconcelos", "given": "Paulo M." } }, { "id": "Heim-J-A", "name": { "family": "Heim", "given": "Jonathan A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Monteiro-H-S", "name": { "family": "Monteiro", "given": "Hevelyn" }, "orcid": "0000-0002-3797-1869" }, { "id": "Waltenberg-K", "name": { "family": "Waltenberg", "given": "Kathryn" } } ] }, "title": "^(40)Ar/^(39)Ar and (U\u2013Th)/He \u2013 ^4He/^3He geochronology of landscape evolution and channel iron deposit genesis at Lynn Peak, Western Australia", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2013 Elsevier Ltd. Received 10 March 2011; accepted in revised form 28 March 2013; available online 9 April 2013. We thank Graham Broadbent and RT Exploration for logistic\nsupport; UQCMM staff (Ron Rash) for help during microanalysis; Peter Colls for sample preparation; Janet Sisterson for help with proton-irradiation, and Lindsey Hedges for help with (U\u2013Th)/He analyses, and Albert Mostert for interpretation of synchrotron results. This project was partly funded by ARC DP0666925, UQ-APA scholarships to J.A.H. and K.W., and an UQ-AGES scholarship to H.M. Gilles Ruffet, and four anonymous reviewers provided useful suggestions for improving the original submission. Peter Reiners provided excellent editorial handling and his suggestions were valuable in improving this manuscript. Associate editor: Marc Norman.\n\nSupplemental Material - mmc1.xls
Supplemental Material - mmc2.xls
Supplemental Material - mmc3.doc
Supplemental Material - mmc4.xls
", "abstract": "(U\u2013Th)/He geochronology of authigenic goethite cements from the Lynn Peak channel iron deposit (CID), Hamersley Province, Western Australia, reveals a history of mineral precipitation ranging from ca. 33 to 14 Ma. Massive goethites from nearby weathering profiles at Roy Hill North, a possible source of detrital material during the aggradation of the Lynn Peak channels, yield (U\u2013Th)/He results as old as ca. 64 Ma. The combination of (U\u2013Th)/He geochronology with incremental outgassing ^4He/^3He studies on proton-irradiated samples reveals that Lynn Peak goethites host radiogenic ^4He in low retentivity (LRD) and high retentivity (HRD) domains and that the HRDs account for most of the sample mass and have lost very little of their original ^4He over geologic time. Such high retentivity is especially notable given the goethites were collected from the surface, where they were subject to significant heating by solar irradiation. Minor contamination by detrital fragments of potentially ^4He-rich primary phases (e.g., rutile, ilmenite, zircon) occurs in some samples. Fortunately, the ^4He/^3He method permits characterization of this extraneous ^4He component, which is small (<10 wt.% of the total ^4He in the goethite) and can be corrected out in estimating the goethite formation age. These results indicate that the Lynn Peak channel was already aggraded and undergoing goethite cementation by ca. 33 Ma.\nThe history of aggradation and channel cementation independently measured through ^(40)Ar/^(39)Ar geochronology is consistent with that obtained from the (U\u2013Th)/He and ^4He/^3He record. Laser incremental-heating ^(40)Ar/^(39)Ar geochronology of detrital and authigenic Mn oxides, primarily cryptomelane (KMn_8O_(16)\u00b7xH_2O), from the same locality in the Lynn Peak channel reveals that detrital oxides are older than ca. 44 Ma (and as old as ca. 65 Ma) and authigenic oxides are younger than ca. 35 Ma and as young as ca. 16 Ma. Authigenic cryptomelane precipitation and channel cementation occurred throughout the Miocene, with a particularly strong period at around 20 Ma. The ^(40)Ar/^(39)Ar geochronological results suggest that regional weathering profiles, developed before 44 Ma and possibly as early as ca. 65 Ma, were incised and partially eroded in the 44\u201335 Ma interval. Semi-arid conditions promoted the transport of large volumes of sediments, aggrading the regional drainage system. Metasomatic reactions in the aggraded channels caused the ferruginization and, in some places, manganese replacement of the CIDs; goethite and K\u2013Mn oxide cementation continued throughout the Oligocene and Miocene. Post-Miocene aridification contributed to the preservation of the cemented channel sediments, forming some of the largest readily mineable iron ore deposits on earth.", "date": "2013-09-15", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "117", "publisher": "Elsevier", "pagerange": "283-312", "id_number": "CaltechAUTHORS:20131003-132552675", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131003-132552675", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "ARC", "grant_number": "DP0666925" }, { "agency": "UQ-APA scholarships" }, { "agency": "UQ-AGES scholarship" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2013.03.037", "primary_object": { "basename": "mmc3.doc", "url": "https://authors.library.caltech.edu/records/1hszg-9gj27/files/mmc3.doc" }, "related_objects": [ { "basename": "mmc4.xls", "url": "https://authors.library.caltech.edu/records/1hszg-9gj27/files/mmc4.xls" }, { "basename": "mmc1.xls", "url": "https://authors.library.caltech.edu/records/1hszg-9gj27/files/mmc1.xls" }, { "basename": "mmc2.xls", "url": "https://authors.library.caltech.edu/records/1hszg-9gj27/files/mmc2.xls" } ], "resource_type": "article", "pub_year": "2013", "author_list": "Vasconcelos, Paulo M.; Heim, Jonathan A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/d6f6m-v8121", "eprint_id": 119715, "eprint_status": "archive", "datestamp": "2023-08-22 09:54:51", "lastmod": "2023-10-25 16:45:16", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mahaffy-Paul-R", "name": { "family": "Mahaffy", "given": "Paul R." }, "orcid": "0000-0003-1896-1726" }, { "id": "Webster-Christopher-R", "name": { "family": "Webster", "given": "Christopher R." } }, { "name": { "family": "Atreya", "given": "Sushil K." }, "orcid": "0000-0002-1972-1815" }, { "name": { "family": "Franz", "given": "Heather" }, "orcid": "0000-0001-9716-5597" }, { "name": { "family": "Wong", "given": "Michael" }, "orcid": "0000-0003-2804-5086" }, { "name": { "family": "Conrad", "given": "Pamela G." }, "orcid": "0000-0001-5724-3343" }, { "name": { "family": "Harpold", "given": "Dan" } }, { "name": { "family": "Jones", "given": "John J." } }, { "id": "Leshin-L-A", "name": { "family": "Leshin", "given": "Laurie A." } }, { "name": { "family": "Manning", "given": "Heidi" } }, { "name": { "family": "Owen", "given": "Tobias" } }, { "name": { "family": "Pepin", "given": "Robert O." } }, { "name": { "family": "Squyres", "given": "Steven" } }, { "name": { "family": "Trainer", "given": "Melissa" }, "orcid": "0000-0003-1106-8580" }, { "name": { "family": "Kemppinen", "given": "Osku" }, "orcid": "0000-0002-7490-2432" }, { "name": { "family": "Bridges", "given": "Nathan" }, "orcid": "0000-0002-6790-6793" }, { "name": { "family": "Johnson", "given": "Jeffrey R." } }, { "name": { "family": "Minitti", "given": "Michelle" }, "orcid": "0000-0003-4715-4544" }, { "name": { "family": "Cremers", "given": "David" } }, { "name": { "family": "Bell", "given": "James F." }, "orcid": "0000-0002-2006-4074" }, { "name": { "family": "Edgar", "given": "Lauren" }, "orcid": "0000-0001-7512-7813" }, { "name": { "family": "Farmer", "given": "Jack" } }, { "name": { "family": "Godber", "given": "Austin" } }, { "name": { "family": "Wadhwa", "given": "Meenakshi" }, "orcid": "0000-0001-9187-1255" }, { "name": { "family": "Wellington", "given": "Danika" }, "orcid": "0000-0002-2130-0075" }, { "name": { "family": "McEwan", "given": "Ian" } }, { "name": { "family": "Newman", "given": "Claire" }, "orcid": "0000-0001-9990-8817" }, { "name": { "family": "Richardson", "given": "Mark" }, "orcid": "0000-0003-2620-7387" }, { "name": { "family": "Charpentier", "given": "Antoine" } }, { "name": { "family": "Peret", "given": "Laurent" } }, { "name": { "family": "King", "given": "Penelope" } }, { "name": { "family": "Blank", "given": "Jennifer" } }, { "name": { "family": "Weigle", "given": "Gerald" } }, { "name": { "family": "Schmidt", "given": "Mariek" } }, { "name": { "family": "Li", "given": "Shuai" } }, { "name": { "family": "Milliken", "given": "Ralph" }, "orcid": "0000-0003-3240-4918" }, { "name": { "family": "Robertson", "given": "Kevin" } }, { "name": { "family": "Sun", "given": "Vivian" }, "orcid": "0000-0003-1480-7369" }, { "id": "Baker-M-B", "name": { "family": "Baker", "given": "Michael" } }, { "id": "Edwards-Christopher", "name": { "family": "Edwards", "given": "Christopher" } }, { "id": "Ehlmann-B-L", "name": { "family": "Ehlmann", "given": "Bethany" }, "orcid": "0000-0002-2745-3240" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth" }, "orcid": "0000-0002-7846-7546" }, { "id": "Griffes-Jennifer", "name": { "family": "Griffes", "given": "Jennifer" } }, { "id": "Grotzinger-J-P", "name": { "family": "Grotzinger", "given": "John" }, "orcid": "0000-0001-9324-1257" }, { "id": "Miller-H-B-D", "name": { "family": "Miller", "given": "Hayden" }, "orcid": "0000-0001-7305-928X" }, { "id": "Newcombe-Megan-E", "name": { "family": "Newcombe", "given": "Megan" }, "orcid": "0000-0002-8450-768X" }, { "id": "Pilorget-Cedric", "name": { "family": "Pilorget", "given": "Cedric" } }, { "id": "Rice-Melissa-S", "name": { "family": "Rice", "given": "Melissa" }, "orcid": "0000-0002-8370-4139" }, { "id": "Siebach-Kirsten", "name": { "family": "Siebach", "given": "Kirsten" }, "orcid": "0000-0002-6628-6297" }, { "id": "Stack-Kathryn-M", "name": { "family": "Stack", "given": "Katie" }, "orcid": "0000-0003-3444-6695" }, { "id": "Stolper-E-M", "name": { "family": "Stolper", "given": "Edward" }, "orcid": "0000-0001-8008-8804" }, { "name": { "family": "Brunet", "given": "Claude" } }, { "name": { "family": "Hipkin", "given": "Victoria" } }, { "name": { "family": "L\u00e9veill\u00e9", "given": "Richard" } }, { "name": { "family": "Marchand", "given": "Genevi\u00e8ve" } }, { "name": { "family": "Sobr\u00f3n S\u00e1nchez", "given": "Pablo" } }, { "name": { "family": "Favot", "given": "Laurent" } }, { "name": { "family": "Cody", "given": "George" } }, { "name": { "family": "Steele", "given": "Andrew" }, "orcid": "0000-0001-9643-2841" }, { "name": { "family": "Fl\u00fcckiger", "given": "Lorenzo" } }, { "name": { "family": "Lees", "given": "David" } }, { "name": { "family": "Nefian", "given": "Ara" } }, { "name": { "family": "Martin", "given": "Mildred" } }, { "name": { "family": "Gailhanou", "given": "Marc" } }, { "name": { "family": "Westall", "given": "Frances" } }, { "name": { "family": "Isra\u00ebl", "given": "Guy" } }, { "name": { "family": "Agard", "given": "Christophe" } }, { "name": { "family": "Baroukh", "given": "Julien" } }, { "name": { "family": "Donny", "given": "Christophe" } }, { "name": { "family": "Gaboriaud", "given": "Alain" } }, { "name": { "family": "Guillemot", "given": "Philippe" } }, { "name": { "family": "Lafaille", "given": "Vivian" } }, { "name": { "family": "Lorigny", "given": "Eric" } }, { "name": { "family": "Paillet", "given": "Alexis" } }, { "name": { "family": "P\u00e9rez", "given": "Ren\u00e9" } }, { "name": { "family": "Saccoccio", "given": "Muriel" } }, { "name": { "family": "Yana", "given": "Charles" } }, { "name": { "family": "Armiens-Aparicio", "given": "Carlos" } }, { "name": { "family": "Caride Rodr\u00edguez", "given": "Javier" } }, { "name": { "family": "Carrasco Bl\u00e1zquez", "given": "Isa\u00edas" } }, { "name": { "family": "G\u00f3mez G\u00f3mez", "given": "Felipe" } }, { "name": { "family": "G\u00f3mez-Elvira", "given": "Javier" } }, { "name": { "family": "Hettrich", "given": "Sebastian" } }, { "name": { "family": "Malvitte", "given": "Alain Lepinette" } }, { "name": { "family": "Mar\u00edn Jim\u00e9nez", "given": "Mercedes" } }, { "name": { "family": "Mart\u00ednez-Fr\u00edas", "given": "Jes\u00fas" } }, { "name": { "family": "Mart\u00edn-Soler", "given": "Javier" } }, { "name": { "family": "Mart\u00edn-Torres", "given": "F. Javier" } }, { "name": { "family": "Molina Jurado", "given": "Antonio" } }, { "name": { "family": "Mora-Sotomayor", "given": "Luis" } }, { "name": { "family": "Mu\u00f1oz Caro", "given": "Guillermo" } }, { "name": { "family": "Navarro L\u00f3pez", "given": "Sara" } }, { "name": { "family": "Peinado-Gonz\u00e1lez", "given": "Ver\u00f3nica" } }, { "name": { "family": "Pla-Garc\u00eda", "given": "Jorge" } }, { "name": { "family": "Rodriguez Manfredi", "given": "Jos\u00e9 Antonio" } }, { "name": { "family": "Romeral-Planell\u00f3", "given": "Julio Jos\u00e9" } }, { "name": { "family": "Sans Fuentes", "given": "Sara Alejandra" } }, { "name": { "family": "Sebastian Martinez", "given": "Eduardo" } }, { "name": { "family": "Torres Redondo", "given": "Josefina" } }, { "name": { "family": "Urqui-O'Callaghan", "given": "Roser" } }, { "name": { "family": "Zorzano Mier", "given": "Mar\u00eda-Paz" } }, { "name": { "family": "Chipera", "given": "Steve" } }, { "name": { "family": "Lacour", "given": "Jean-Luc" } }, { "name": { "family": "Mauchien", "given": "Patrick" } }, { "name": { "family": "Sirven", "given": "Jean-Baptiste" } }, { "name": { "family": "Fair\u00e9n", "given": "Alberto" }, "orcid": "0000-0002-2938-6010" }, { "name": { "family": "Hayes", "given": "Alexander" }, "orcid": "0000-0001-6397-2630" }, { "name": { "family": "Joseph", "given": "Jonathan" } }, { "name": { "family": "Sullivan", "given": "Robert" }, "orcid": "0000-0003-4191-598X" }, { "name": { "family": "Thomas", "given": "Peter" } }, { "name": { "family": "Dupont", "given": "Audrey" } }, { "name": { "family": "Lundberg", "given": "Angela" } }, { "name": { "family": "Melikechi", "given": "Noureddine" } }, { "name": { "family": "Mezzacappa", "given": "Alissa" } }, { "name": { "family": "DeMarines", "given": "Julia" } }, { "name": { "family": "Grinspoon", "given": "David" }, "orcid": "0000-0002-2265-7551" }, { "name": { "family": "Reitz", "given": "G\u00fcnther" } }, { "name": { "family": "Prats", "given": 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"name": { "family": "de Pablo Hern\u00e1ndez", "given": "Miguel \u00c1ngel" } }, { "name": { "family": "Blanco \u00c1valos", "given": "Juan Jos\u00e9" } }, { "name": { "family": "Ramos", "given": "Miguel" } }, { "name": { "family": "Kim", "given": "Myung-Hee" } }, { "name": { "family": "Malespin", "given": "Charles" }, "orcid": "0000-0002-5852-5016" }, { "name": { "family": "Plante", "given": "Ianik" } }, { "name": { "family": "Muller", "given": "Jan-Peter" } }, { "name": { "family": "Navarro-Gonz\u00e1lez", "given": "Rafael" } }, { "name": { "family": "Ewing", "given": "Ryan" }, "orcid": "0000-0001-6337-610X" }, { "name": { "family": "Boynton", "given": "William" } }, { "name": { "family": "Downs", "given": "Robert" }, "orcid": "0000-0002-8380-7728" }, { "name": { "family": "Fitzgibbon", "given": "Mike" } }, { "name": { "family": "Harshman", "given": "Karl" } }, { "name": { "family": "Morrison", "given": "Shaunna" }, "orcid": "0000-0002-1712-8057" }, { "name": { "family": "Dietrich", "given": "William" } }, { "name": { "family": "Kortmann", "given": "Onno" } }, { "name": { "family": "Palucis", "given": "Marisa" }, "orcid": "0000-0003-0034-5810" }, { "name": { "family": "Sumner", "given": "Dawn Y." }, "orcid": "0000-0002-7343-2061" }, { "name": { "family": "Williams", "given": "Amy" }, "orcid": "0000-0001-6299-0845" }, { "name": { "family": "Lugmair", "given": "G\u00fcnter" } }, { "name": { "family": "Wilson", "given": "Michael A." } }, { "name": { "family": "Rubin", "given": "David" }, "orcid": "0000-0003-1169-1452" }, { "name": { "family": "Jakosky", "given": "Bruce" }, "orcid": "0000-0002-0758-9976" }, { "name": { "family": "Balic-Zunic", "given": "Tonci" } }, { "name": { "family": "Frydenvang", "given": "Jens" }, "orcid": "0000-0001-9294-1227" }, { "name": { "family": "Jensen", "given": "Jaqueline Kl\u00f8vgaard" } }, { "name": { "family": "Kinch", "given": "Kjartan" }, "orcid": "0000-0002-4629-8880" }, { "name": { "family": "Koefoed", "given": "Asmus" } }, { "name": { "family": "Madsen", "given": "Morten Bo" }, "orcid": "0000-0001-8909-5111" }, { "name": { "family": "Svane Stipp", "given": "Susan Louise" } }, { "name": { "family": "Boyd", "given": "Nick" } }, { "name": { "family": "Campbell", "given": "John L." } }, { "name": { "family": "Gellert", "given": "Ralf" }, "orcid": "0000-0001-7928-834X" }, { "name": { "family": "Perrett", "given": "Glynis" } }, { "name": { "family": "Pradler", "given": "Irina" } }, { "name": { "family": "VanBommel", "given": "Scott" }, "orcid": "0000-0002-6565-0827" }, { "name": { "family": "Jacob", "given": "Samantha" }, "orcid": "0000-0001-9950-1486" }, { "name": { "family": "Rowland", "given": "Scott K." }, "orcid": "0000-0003-3943-1492" }, { "name": { "family": "Atlaskin", "given": "Evgeny" } }, { "name": { "family": "Savij\u00e4rvi", "given": "Hannu" } }, { "name": { "family": "Boehm", "given": "Eckart" } }, { "name": { "family": "B\u00f6ttcher", "given": "Stephan" } }, { "name": { "family": "Burmeister", "given": "S\u00f6nke" } }, { "name": { "family": "Guo", "given": "Jingnan" }, "orcid": "0000-0002-8707-076X" }, { "name": { "family": "K\u00f6hler", "given": "Jan" } }, { "name": { "family": "Mart\u00edn Garc\u00eda", "given": "C\u00e9sar" } }, { "name": { "family": "Mueller-Mellin", "given": "Reinhold" } }, { "name": { "family": "Wimmer-Schweingruber", "given": "Robert F." }, "orcid": "0000-0002-7388-173X" }, { "name": { "family": "Bridges", "given": "John C." }, "orcid": "0000-0002-9579-5779" }, { "name": { "family": "McConnochie", "given": "Timothy" } }, { "name": { "family": "Benna", "given": "Mehdi" } }, { "name": { "family": "Bower", "given": "Hannah" } }, { "name": { "family": "Brunner", "given": "Anna" } }, { "name": { "family": "Blau", "given": "Hannah" } }, { "name": { "family": "Boucher", "given": "Thomas" } }, { "name": { "family": "Carmosino", "given": "Marco" } }, { "name": { "family": "Elliott", "given": "Harvey" } }, { "name": { "family": "Halleaux", "given": "Douglas" } }, { "name": { "family": "Renn\u00f3", "given": "Nilton" } }, { "name": { "family": "Elliott", "given": "Beverley" } }, { "name": { "family": "Spray", "given": "John" } }, { "name": { "family": "Thompson", "given": "Lucy" }, "orcid": "0000-0002-5444-952X" }, { "name": { "family": "Gordon", "given": "Suzanne" } }, { "name": { "family": "Newsom", "given": "Horton" }, "orcid": "0000-0002-4358-8161" }, { "name": { "family": "Ollila", "given": "Ann" } }, { "name": { "family": "Williams", "given": "Joshua" } }, { "name": { "family": "Vasconcelos", "given": "Paulo" } }, { "name": { "family": "Bentz", "given": "Jennifer" } }, { "name": { "family": "Nealson", "given": "Kenneth" }, "orcid": "0000-0001-5189-3732" }, { "name": { "family": "Popa", "given": "Radu" } }, { "name": { "family": "Kah", "given": "Linda C." }, "orcid": "0000-0001-7172-2033" }, { "name": { "family": "Moersch", "given": "Jeffrey" } }, { "name": { "family": "Tate", "given": "Christopher" } }, { "name": { "family": "Day", "given": "Mackenzie" }, "orcid": "0000-0003-3998-7749" }, { "name": { "family": "Kocurek", "given": "Gary" } }, { "name": { "family": "Hallet", "given": "Bernard" } }, { "name": { "family": "Sletten", "given": "Ronald" } }, { "name": { "family": "Francis", "given": "Raymond" } }, { "name": { "family": "McCullough", "given": "Emily" } }, { "name": { "family": "Cloutis", "given": "Ed" }, "orcid": "0000-0001-7301-0929" }, { "name": { "family": "ten Kate", "given": "Inge Loes" }, "orcid": "0000-0002-1135-1792" }, { "name": { "family": "Kuzmin", "given": "Ruslan" } }, { "name": { "family": "Arvidson", "given": "Raymond" }, "orcid": "0000-0002-2854-0362" }, { "name": { "family": "Fraeman", "given": "Abigail" }, "orcid": "0000-0003-4017-5158" }, { "name": { "family": "Scholes", "given": "Daniel" } }, { "name": { "family": "Slavney", "given": "Susan" } }, { "name": { "family": "Stein", "given": "Thomas" } }, { "name": { "family": "Ward", "given": "Jennifer" } }, { "name": { "family": "Berger", "given": "Jeffrey" } }, { "name": { "family": "Moores", "given": "John E." } } ] }, "title": "Abundance and Isotopic Composition of Gases in the Martian Atmosphere from the Curiosity Rover", "ispublished": "pub", "full_text_status": "public", "keywords": "Multidisciplinary", "abstract": "Volume mixing and isotope ratios secured with repeated atmospheric measurements taken with the Sample Analysis at Mars instrument suite on the Curiosity rover are: carbon dioxide (CO\u2082), 0.960(\u00b10.007); argon-40 (\u2074\u2070Ar), 0.0193(\u00b10.0001); nitrogen (N\u2082), 0.0189(\u00b10.0003); oxygen, 1.45(\u00b10.09) \u00d7 10\u207b\u00b3; carbon monoxide, < 1.0 \u00d7 10\u207b\u00b3; and \u2074\u2070Ar/\u00b3\u2076Ar, 1.9(\u00b10.3) \u00d7 10\u00b3. The \u2074\u2070Ar/N\u2082 ratio is 1.7 times greater and the \u2074\u2070Ar/\u00b3\u2076Ar ratio 1.6 times lower than values reported by the Viking Lander mass spectrometer in 1976, whereas other values are generally consistent with Viking and remote sensing observations. The \u2074\u2070Ar/\u00b3\u2076Ar ratio is consistent with martian meteoritic values, which provides additional strong support for a martian origin of these rocks. The isotopic signature \u03b4\u00b9\u00b3C from CO\u2082 of ~45 per mil is independently measured with two instruments. This heavy isotope enrichment in carbon supports the hypothesis of substantial atmospheric loss.", "date": "2013-07-19", "date_type": "published", "publication": "Science", "volume": "341", "number": "6143", "publisher": "American Association for the Advancement of Science", "pagerange": "263-266", "id_number": "CaltechAUTHORS:20230307-649704000.12", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-649704000.12", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "corp_creators": { "items": [ "MSL Science Team" ] }, "doi": "10.1126/science.1237966", "resource_type": "article", "pub_year": "2013", "author_list": "Mahaffy, Paul R.; Webster, Christopher R.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/qswm6-pcj49", "eprint_id": 38537, "eprint_status": "archive", "datestamp": "2023-08-19 20:21:00", "lastmod": "2023-10-23 20:33:30", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Hurowitz-J-A", "name": { "family": "Hurowitz", "given": "J. A." }, "orcid": "0000-0002-5857-8652" }, { "id": "Asimow-P-D", "name": { "family": "Asimow", "given": "Paul D." }, "orcid": "0000-0001-6025-8925" }, { "id": "Jacobson-N-S", "name": { "family": "Jacobson", "given": "N. S." } }, { "id": "Cartwright-J-A", "name": { "family": "Cartwright", "given": "J. A." } } ] }, "title": "A double-spike method for K\u2013Ar measurement: A technique\n for high precision in situ dating on Mars and other\n planetary surfaces", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2013 Elsevier Ltd. Received 4 December 2012; accepted in revised form 5 February 2013; available online 16 February 2013. We thank Paul Renne for suggesting and providing the Viluy Traps basalt sample and Tim Becker for facilitating the irradiation of our spike glass. We thank Leah Morgan, Pete Burnard, and two anonymous reviewers for helpful suggestions. This work could not have occurred without the generous and patient support of the Keck Institute for Space Studies. This research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Agency (JAH).\nAssociate editor: Pete Burnard", "abstract": "A new method for K\u2013Ar dating using a double isotope dilution technique is proposed and demonstrated. The method is designed to eliminate known difficulties facing in situ dating on planetary surfaces, especially instrument complexity and power availability. It may also have applicability in some terrestrial dating applications. Key to the method is the use of a solid tracer spike enriched in both ^(39)Ar and ^(41)K. When mixed with lithium borate flux in a Knudsen effusion cell, this tracer spike and a sample to be dated can be successfully fused and degassed of Ar at <1000 \u00b0C. The evolved ^(40)Ar^\u2217/^(39)Ar ratio can be measured to high precision using noble gas mass spectrometry. After argon measurement the sample melt is heated to a slightly higher temperature (\u223c1030 \u00b0C) to volatilize potassium, and the evolved ^(39)K/(41)K ratio measured by Knudsen effusion mass spectrometry. Combined with the known composition of the tracer spike, these two ratios define the K\u2013Ar age using a single sample aliquot and without the need for extreme temperature or a mass determination. In principle the method can be implemented using a single mass spectrometer.\nExperiments indicate that quantitative extraction of argon from a basalt sample occurs at a sufficiently low temperature that potassium loss in this step is unimportant. Similarly, potassium isotope ratios measured in the Knudsen apparatus indicate good sample-spike equilibration and acceptably small isotopic fractionation. When applied to a flood basalt from the Viluy Traps, Siberia, a K\u2013Ar age of 351 \u00b1 19 Ma was obtained, a result within 1% of the independently known age. For practical reasons this measurement was made on two separate mass spectrometers, but a scheme for combining the measurements in a single analytical instrument is described. Because both parent and daughter are determined by isotope dilution, the precision on K\u2013Ar ages obtained by the double isotope dilution method should routinely approach that of a pair of isotope ratio determinations, likely better than \u00b15%.", "date": "2013-06-01", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "110", "publisher": "Elsevier", "pagerange": "1-12", "id_number": "CaltechAUTHORS:20130516-095248373", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130516-095248373", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Keck Institute for Space Studies (KISS)" }, { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "Keck-Institute-for-Space-Studies" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2013.02.010", "resource_type": "article", "pub_year": "2013", "author_list": "Farley, K. A.; Hurowitz, J. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/b03fv-5j487", "eprint_id": 38680, "eprint_status": "archive", "datestamp": "2023-08-22 09:12:17", "lastmod": "2023-10-23 22:40:47", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Piacentini-T", "name": { "family": "Piacentini", "given": "Thiago" } }, { "id": "Vasconcelos-P-M", "name": { "family": "Vasconcelos", "given": "Paulo M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "^(40)Ar/^(39)Ar constraints on the age and thermal history of the Urucum Neoproterozoic banded iron-formation, Brazil", "ispublished": "pub", "full_text_status": "public", "keywords": "Ar-40/Ar-39; Neoproterozoic; Banded iron-formation; Urucum; Brasiliano", "note": "\u00a9 2013 Elsevier B.V.\n\nReceived 6 January 2012;\nReceived in revised form 3 December 2012;\nAccepted 3 January 2013;\nAvailable online 16 January 2013.\n\nThis research project is possible thanks to the grant issued\nto T.P. by CNPq (GDE200895/2009-5). We would like to express\nour gratitude to the mining companies of the Urucum district\n(Urucum Minera\u00e7\u00e3o, Minera\u00e7\u00e3o Corumbaense Reunida, and Vale)\nfor allowing us access and geological information. We are grateful to Xiaodong Deng, from the GPMR-CUG for the SEM images.\nWe are also grateful to staff of the CMM-UQ, particularly Ronald Rasch and Ying Yu for their assistance during the EMPA analysis, and, Benjamin Cohen and David Thiede (UQ-AGES), during the isotopic analysis. T.P. also thanks Bernardo Freitas for insightful discussions. The painstaking review of Umberto Cordani, an anonymous\nreviewer, and the editor Randal Parrish, greatly improved the manuscript.\n\nSupplemental Material - mmc1.docx
Supplemental Material - mmc2.xlsx
", "abstract": "Urucum is one of the youngest banded iron-formations (BIFs) yet its exact age remains uncertain. ^(40)Ar/^(39)Ar geochronology on late-diagenetic to early metamorphic cryptomelane from the Urucum sequence reveals a minimum depositional age of 587 \u00b1 7 Ma. Metamorphic braunite age spectra yield flat segments defining apparent ages of 547 \u00b1 3 Ma to 513 \u00b1 4 Ma, interpreted as recrystallization or cooling ages. Metamorphic muscovite grains from a meta-arkose interbedded with the BIF yield reproducible plateau ages of 513 \u00b1 3 Ma. Cryptomelane ages are interpreted to record the minimum timing of the extensional tectonic events that generated the graben systems at the southeastern border of the Amazon craton, including the Chiquitos-Tucavaca aulacogen and the Jacadigo Basin, which hosts the Urucum banded iron-formation. Structurally controlled hydrothermal alteration resulted in crystallization of braunite and muscovite during the interval between 547 and 513 Ma coeval with post-collisional decompression that resulted in granite emplacement (e.g., S\u00e3o Vicente Granite) in the Paraguay Belt. Subsequent uplift and erosion of the Precambrian sequence possibly succeeded metamorphism. A chemically distinct cryptomelane generation identified in surface samples yield ca. 60 Ma results. These ages provide evidence for supergene recrystallization after exhumation in the Mesozoic/Cenozoic.\n^(40)Ar/^(39)Ar systematics implies that the oldest cryptomelane samples experienced Ar-loss probably via thermally induced diffusion. This suggests that the Urucum BIF was buried and heated to significant temperatures in the late Proterozoic, consistent with present mineralogy and isotopic composition that do not reflect the original characteristics of the depositional environment.", "date": "2013-05", "date_type": "published", "publication": "Precambrian Research", "volume": "228", "publisher": "Elsevier", "pagerange": "48-62", "id_number": "CaltechAUTHORS:20130528-090838756", "issn": "0301-9268", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130528-090838756", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "CNPq", "grant_number": "GDE200895/2009-5" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.precamres.2013.01.002", "primary_object": { "basename": "mmc1.docx", "url": "https://authors.library.caltech.edu/records/b03fv-5j487/files/mmc1.docx" }, "related_objects": [ { "basename": "mmc2.xlsx", "url": "https://authors.library.caltech.edu/records/b03fv-5j487/files/mmc2.xlsx" } ], "resource_type": "article", "pub_year": "2013", "author_list": "Piacentini, Thiago; Vasconcelos, Paulo M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/fz5xj-d7173", "eprint_id": 38538, "eprint_status": "archive", "datestamp": "2023-08-22 09:07:36", "lastmod": "2023-10-23 20:33:33", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flowers-R-M", "name": { "family": "Flowers", "given": "R. M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Response to Comments on \"Apatite ^4He/^3He and (U-Th)/He Evidence for an Ancient Grand Canyon\"", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2013 American Association for the Advancement of Science. \n\nReceived for publication 22 January 2013. \nAccepted for publication 25 February 2013. \n\nThis work was supported by NSF grant\nEAR-1019896 to K.A.F.", "abstract": "We reiterate that geological observations do not require Grand Canyon carving coeval with\nColorado River integration. (U-Th)/He data from the western canyon, totaling 29 reproducible\nanalyses from six samples and two labs, compellingly support an ancient canyon. Three dispersed\nanalyses from one anomalous sample do not refute this conclusion, nor do the claimed\nshortcomings of our modeling have validity.", "date": "2013-04-12", "date_type": "published", "publication": "Science", "volume": "340", "number": "6129", "publisher": "American Association for the Advancement of Science", "pagerange": "143-144", "id_number": "CaltechAUTHORS:20130516-102216881", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130516-102216881", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1019896" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.1234203", "resource_type": "article", "pub_year": "2013", "author_list": "Flowers, R. M. and Farley, K. A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/j9mrm-jej38", "eprint_id": 36794, "eprint_status": "archive", "datestamp": "2023-08-22 08:04:38", "lastmod": "2023-10-23 15:47:34", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Schmitt-A-K", "name": { "family": "Schmitt", "given": "Axel K." } }, { "id": "Mart\u00edn-A", "name": { "family": "Mart\u00edn", "given": "Arturo" } }, { "id": "Stockli-D-F", "name": { "family": "Stockli", "given": "Daniel F." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Lovera-O-M", "name": { "family": "Lovera", "given": "Oscar M." } } ] }, "title": "(U-Th)/He zircon and archaeological ages for a late prehistoric eruption in the Salton Trough (California, USA)", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2012 Geological Society of America. Received 16 May 2012. Revision received 6 June 2012. Accepted 11 June 2012. Published online 15 October 2012. We thank W. Elders for providing sample I70\u201324, L. Hedges and R. Kislitsyn for (U-Th)/He analytical assistance, and H. Zou and C. Shen for whole-rock U-Th isotope data. M. Dahdul, J. Dietler, M.C. Hall, D. Laylander, S., Shackley, and A. Porcayo-Michelini\nshared helpful insights into obsidian archaeology. We thank reviewers C. Bacon, T. Fischer, and editors A. Barth and S. Wyld. This work was supported by grants through UC-MEXUS (University of California Institute for Mexico and the United States) CN 07-60 and National Science Foundation MARGINS grant EAR-0948162. The ion microprobe facility at\nthe University of California\u2013Los Angeles is partly \nsupported by a grant from the Instrumentation and Facilities Program, Division of Earth Sciences, National\nScience Foundation.", "abstract": "U-Th and (U-Th)/He zircon geochronology redefines the timing of volcanic activity in the Salton Trough (Southern California, USA), the subaerial extension of the incipiently oceanic Gulf of California. U-series disequilibrium corrected (U-Th)/He zircon analyses for a granophyre ejecta clast from the Red Island rhyolite dome indicate an eruption age of 2480 \u00b1 470 a (calendric dates between 0 and 940 Before Common Era, BCE; error at 95% confidence). This eruption age is supported by U-Th zircon crystallization ages for two obsidian-bearing lavas: Red Island (the host for the granophyre) and Obsidian Butte, a prehistoric quarry for obsidian that is widely distributed in southern California and northern Mexico archaeological sites. Lavas and granophyre display overlapping zircon crystallization age distributions that support field and compositional evidence that they are cogenetic and contemporaneous. The (U-Th)/He eruption age is younger and significantly more precise than previous ages for these volcanoes, and is the first indication that the eruption of obsidian flows coincided with human presence in the region. A late prehistoric eruption age agrees with the absence of the Obsidian Butte lithic source among early prehistoric cultural artifacts, previously attributed to submergence of the quarry location during hypothesized persistent flooding by ancient Lake Cahuilla.", "date": "2013-01", "date_type": "published", "publication": "Geology", "volume": "41", "number": "1", "publisher": "Geological Society of America", "pagerange": "7-10", "id_number": "CaltechAUTHORS:20130206-131839517", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130206-131839517", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "University of California Institute for Mexico and the United States (UC-MEXUS)", "grant_number": "CN 07-60" }, { "agency": "NSF MARGINS", "grant_number": "EAR-0948162" }, { "agency": "NSF Division of Earth Sciences, Instrumentation and Facilities Program" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/G33634.1", "resource_type": "article", "pub_year": "2013", "author_list": "Schmitt, Axel K.; Mart\u00edn, Arturo; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/v6fyq-cvt65", "eprint_id": 36477, "eprint_status": "archive", "datestamp": "2023-08-22 07:59:15", "lastmod": "2023-10-20 23:12:05", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flowers-R-M", "name": { "family": "Flowers", "given": "R. M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Apatite ^4He/^3He and (U-Th)/He Evidence for an Ancient Grand Canyon", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2012 American Association for the Advancement of Science. \n\nReceived 27 August 2012; accepted 7 November 2012.\nPublished online 29 November 2012.\n\nThis work was supported by NSF grant EAR-1019896 to K.A.F. The data reported in this paper are tabulated in the supplementary materials. We thank B. Wernicke for discussion.", "abstract": "The Grand Canyon is one of the most dramatic features on Earth, yet when and why it was carved have been controversial topics for more than 150 years. Here, we present apatite ^4He/^3He thermochronometry data from the Grand Canyon basement that tightly constrain the near-surface cooling history associated with canyon incision. ^4He/^3He spectra for eastern Grand Canyon apatites of differing He date, radiation damage, and U-Th zonation yield a self-consistent cooling history that substantially validates the He diffusion kinetic model applied here. Similar data for the western Grand Canyon provide evidence that it was excavated to within a few hundred meters of modern depths by ~70 million years ago (Ma), in contrast to the conventional model in which the entire canyon was carved since 5 to 6 Ma.", "date": "2012-12-21", "date_type": "published", "publication": "Science", "volume": "338", "number": "6114", "publisher": "American Association for the Advancement of Science", "pagerange": "1616-1619", "id_number": "CaltechAUTHORS:20130118-104945109", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130118-104945109", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.1229390", "resource_type": "article", "pub_year": "2012", "author_list": "Flowers, R. M. and Farley, K. A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/43cr4-ma633", "eprint_id": 36785, "eprint_status": "archive", "datestamp": "2023-08-22 07:57:03", "lastmod": "2023-10-23 15:46:40", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Flowers-R-M", "name": { "family": "Flowers", "given": "R. M." } } ] }, "title": "(U\u2013Th)/Ne and multidomain (U\u2013Th)/He systematics of a hydrothermal hematite from eastern Grand Canyon", "ispublished": "pub", "full_text_status": "public", "keywords": "geochronology; helium dating; multidomain feldspar dating; Grand Canyon", "note": "\u00a9 2012 Elsevier B.V. Received 10 July 2012. Received in revised form 9 October 2012. Accepted 10 October 2012. Editor: B. Marty. Available online 9 November 2012. This work was supported by NSF Grants EAR-1019896 and EAR-1144500 and benefitted from discussions with Brian Wernicke, Paul Asimow, and George Rossman. We thank Dan Stockli and Cecile Gautheron for thoughtful reviews.\n\nSupplemental Material - mmc4.xlsx
Supplemental Material - mmc5.xlsx
Supplemental Material - mmc6.xlsx
Supplemental Material - mmc7.docx
", "abstract": "A hydrothermal hematite from the Redwall Limestone in eastern Grand Canyon (Arizona, USA) was analyzed for (U\u2013Th)/He and (U\u2013Th)/Ne systematics. The dense polycrystalline aggregate has U and Th concentrations of \u223c16 ppm each. Neon produced by \u03b1 particle capture on ^(18)O is abundant in the sample\u2014it constitutes \u223c90% of total ^(21)Ne and indicates a (U\u2013Th)/Ne age of 217\u00b15 Ma. This value provides a lower bound for the formation age of the sample but detailed interpretation is not possible given the current absence of neon diffusion data for hematite. The 130\u00b12 Ma (U\u2013Th)/He age is much younger than the Ne age and therefore must be a cooling age. Highly reproducible step-heating He release experiments reveal the existence of a spectrum of diffusion domain sizes spanning about 3 orders of magnitude in radius, corresponding to He closure temperatures ranging from <0 to \u223c150 \u00b0C. These domains may correspond to crystallites in the specimen, which are observed to range from smaller than a few nm to a few \u03bcm. ^4He/^3He age spectra acquired from the same experiments define a distinctive sigmoidal shape with step ages increasing monotonically from 0 to \u223c210 Ma. This pattern clearly records the presence of the multiple domains as the hematite acquired its radiogenic helium. Coupling of the ^4He/^3He spectra and the diffusion data allow modeling of permissible time\u2013temperature paths experienced by the hematite. These paths can be compared with independent thermal history reconstructions for eastern Grand Canyon characterized by \u223c170 m.yr. of sedimentary burial followed by regional unroofing and canyon incision beginning at \u223c80 Ma. The unroofing portion of the path inferred from the hematite is in good agreement with apatite (U\u2013Th)/He and fission-track data. The results permit rapid cooling in Late Cretaceous\u2013early Tertiary time, suggest a subsequent period of slow cooling through temperatures of \u223c50\u201370 \u00b0C, with accelerated cooling ensuing after 20 Ma. In contrast, the hematite data demand temperatures in some part(s) of the Mesozoic that are at least 100 \u00b0C hotter than expected based on burial depth estimates. This may indicate that the sample experienced a reheating event associated with the passage of fluids similar to those observed at nearby mineralized breccia pipes. Overall these data provide motivation for further work to understand He and Ne behavior in hematite and their potential use in thermochronometry.", "date": "2012-12-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "359", "publisher": "Elsevier", "pagerange": "131-140", "id_number": "CaltechAUTHORS:20130205-113650046", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130205-113650046", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1019896" }, { "agency": "NSF", "grant_number": "EAR-1144500" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2012.10.010", "primary_object": { "basename": "mmc5.xlsx", "url": "https://authors.library.caltech.edu/records/43cr4-ma633/files/mmc5.xlsx" }, "related_objects": [ { "basename": "mmc6.xlsx", "url": "https://authors.library.caltech.edu/records/43cr4-ma633/files/mmc6.xlsx" }, { "basename": "mmc7.docx", "url": "https://authors.library.caltech.edu/records/43cr4-ma633/files/mmc7.docx" }, { "basename": "mmc4.xlsx", "url": "https://authors.library.caltech.edu/records/43cr4-ma633/files/mmc4.xlsx" } ], "resource_type": "article", "pub_year": "2012", "author_list": "Farley, K. A. and Flowers, R. M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/kgabb-zwd93", "eprint_id": 48173, "eprint_status": "archive", "datestamp": "2023-08-22 07:40:09", "lastmod": "2023-10-17 16:42:30", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Cecil-M-R", "name": { "family": "Cecil", "given": "M. Robinson" } }, { "id": "Saleeby-Z", "name": { "family": "Saleeby", "given": "Zorka" } }, { "id": "Le-Pourhiet-L", "name": { "family": "Le Pourhiet", "given": "Laetitia" } }, { "id": "Saleeby-J-B", "name": { "family": "Saleeby", "given": "Jason" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Ken A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "6 Ma subsidence and exhumation of the southeastern San Joaquin Basin, California, in response to mantle lithosphere removal", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2012 Geological Society of America.", "abstract": "New thermo-mechanical models of mantle lithosphere removal from beneath the southern Sierra Nevada, California, predict a complex spatio \u2013 temporal pattern of vertical surface displacements. We evaluate these models by using (U-Th)/He thermochronometry, together with other paleothermometry estimates, to investigate such topographic transients. We target sediments from the Kern Arch, a fan-shaped uplift located in the southeastern San Joaquin Basin, along the western flank of the southern Sierra. Kern Arch stratigraphy provides a unique record of subsidence and exhumation in a sensitive region immediately adjacent to the delaminating mantle lithosphere at depth. Detrital apatite (U-Th)/He ages from Oligo-Miocene sandstones collected in Kern Arch well cores indicate post-depositional heating to temperatures beyond those corresponding with their present burial depths. When integrated with available geologic and stratigraphic constraints, temperature \u2013 time modeling of thermochronometry data suggests partial He loss from apatites at temperatures of 70\u00b0 \u2013 90\u00b0C, followed by exhumation to present burial temperatures of 35\u00b0 \u2013 60\u00b0C since ca. 6 Ma. Assuming a regional late Cenozoic geothermal gradient of 25\u00b0C/km, our results imply 1.0 \u2013 1.6 km of rapid (~ 0.4 mm/yr) burial and subsequent exhumation of southeastern San Joaquin sediments in latest Miocene - Quaternary time. Subtle differences in the maximum temperatures achieved in various wells may reflect differing degrees of tectonic subsidence and sedimentation as a function of distance from the range front. Our results are consistent with estimates of surface subsidence and uplift from Sierran delamination models, which predict a minimum of 0.8 km of subsidence in regions presently associated with mantle lithosphere at depth, and a minimum of 0.6 km of surface uplift in regions where delamination has recently occurred. We attribute the marked pulse of tectonic subsidence in the San Joaquin Basin to viscous coupling between the lower crust and a downwelling mass in the delaminating slab. The ensuing episode of denudation is interpreted to result from the northwestward peeling back of the slab and the associated replacement of dense lithosphere with buoyant asthenosphere.", "date": "2012-11", "date_type": "published", "publication": "Abstracts with Programs - Geological Society of America", "volume": "44", "number": "7", "publisher": "Geological Society of America", "pagerange": "489", "id_number": "CaltechAUTHORS:20140807-095720398", "issn": "0016-7592", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140807-095720398", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "resource_type": "article", "pub_year": "2012", "author_list": "Cecil, M. Robinson; Saleeby, Zorka; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/8ph6x-hkm53", "eprint_id": 32360, "eprint_status": "archive", "datestamp": "2023-08-22 05:53:55", "lastmod": "2023-10-17 23:21:42", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Duvall-A-R", "name": { "family": "Duvall", "given": "Alison R." }, "orcid": "0000-0002-7760-7236" }, { "id": "Clark-M-K", "name": { "family": "Clark", "given": "Marin K." }, "orcid": "0000-0002-6141-8422" }, { "id": "Avdeev-B", "name": { "family": "Avdeev", "given": "Boris" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Chen-Zhengwei", "name": { "family": "Chen", "given": "Zhengwei" } } ] }, "title": "Widespread late Cenozoic increase in erosion rates across the interior of eastern Tibet constrained by detrital low-temperature thermochronometry", "ispublished": "pub", "full_text_status": "public", "keywords": "Tibet; continental tectonics; detrital thermochronometry; erosion", "note": "\u00a9 2012 American Geophysical Union. \n\nReceived 20 June 2011; accepted 26 April 2012; published 8 June 2012. \n\nBoris Avdeev passed away unexpectedly during the final copyediting stages of this manuscript. We recognize his full input to what is published here and wish to dedicate the paper to his memory. His intellectual creativity and adventurous spirit will always inspire us. This work was supported by the NSF grants EAR-0507431, EAR-0908711, EAR-0507788, and EAR-0810067; the National Science Foundation of China (40234040; and the State Key Laboratory of Earthquake Dynamics (LED2008A01). We thank Lindsay Hedges and William Amidon for assistance with sample analyses, John Bershaw and Pei-zhen Zhang for field support, and Nora Lewandowski and Joe Murphy for help with mineral separations. We thank Jim Spotila and Barbara Carrapa for thoughtful and constructive reviews. We also acknowledge Doug Burbank, Nathan Niemi, Eric Kirby, and Peter Molnar for thoughtful discussions about this work.\n\nPublished - Duvall2012p18730Tectonics.pdf
", "abstract": "New detrital low-temperature thermochronometry provides estimates of long-term erosion rates and the timing of initiation of river incision from across the interior of the Tibetan Plateau. We use the erosion history of this region to evaluate proposed models of orogenic development as well as regional climatic events. Erosion histories of the externally drained portion of the east-central Tibetan Plateau are recorded in modern river sands from major rivers across a transect that spans >750 km and covers a region with no published thermochronometric ages. Individual grains from eight catchments were analyzed for apatite (U-Th)/He and fission track thermochronometry. A wide distribution in ages that, in most cases, spans the entire Cenozoic and Late Mesozoic eras requires a long period of slow or no erosion with a relative increase in erosion rate toward the present. We apply a recently developed methodology for inversion of detrital thermochronometric data for three specified erosion scenarios: constant erosion rate, two-stage erosion history, and three-stage erosion history. Modeling results suggest that rates increase by at least an order of magnitude between 11 and 4 Ma following a period of slow erosion across the studied catchments. Synchroneity in accelerated erosion across the whole of the Tibetan Plateau rather than a spatial or temporal progression challenges the widely held notion that the plateau evolved as a steep, northward-propagating topographic front, or that south to north precipitation gradients exert a primary control on erosion rates. Instead, we suggest that accelerated river incision late in the orogen's history relates to regional-scale uplift that occurred in concert with eastern expansion of the plateau.", "date": "2012-06-08", "date_type": "published", "publication": "Tectonics", "volume": "31", "publisher": "American Geophysical Union", "pagerange": "Art. No. TC3014", "id_number": "CaltechAUTHORS:20120711-131942804", "issn": "0278-7407", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120711-131942804", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0507431" }, { "agency": "NSF", "grant_number": "EAR-0908711" }, { "agency": "NSF", "grant_number": "EAR-0507788" }, { "agency": "NSF", "grant_number": "EAR-0810067" }, { "agency": "National Natural Science Foundation of China", "grant_number": "40234040" }, { "agency": "State Key Laboratory of Earthquake Dynamics", "grant_number": "LED2008A01" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2011TC002969", "primary_object": { "basename": "Duvall2012p18730Tectonics.pdf", "url": "https://authors.library.caltech.edu/records/8ph6x-hkm53/files/Duvall2012p18730Tectonics.pdf" }, "resource_type": "article", "pub_year": "2012", "author_list": "Duvall, Alison R.; Clark, Marin K.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/c5p7r-93z44", "eprint_id": 31368, "eprint_status": "archive", "datestamp": "2023-08-22 05:36:53", "lastmod": "2023-10-17 16:07:19", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Montanari-A", "name": { "family": "Montanari", "given": "A." } }, { "id": "Coccioni-R", "name": { "family": "Coccioni", "given": "R." } } ] }, "title": "A record of the extraterrestrial ^3He flux through the Late Cretaceous", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2012 Elsevier Ltd.\n\nReceived 7 October 2011. Accepted 18 January 2012. Available online 3 February 2012.\n\nThis work was partially supported by the U.S. National Science Foundation (OCE-1060877). We thank Scott Farley and Daniel Blado for their contributions to the analytical work and Christian Koeberl for thoughtful early discussions. The manuscript benefitted from reviews by P. Claeys and J. Fritz.", "abstract": "Late Cretaceous (100\u201373 Ma) pelagic limestones were measured for helium concentration and isotopic composition to characterize the interplanetary dust flux using ^(3)He as a tracer. In the Bottaccione section near Gubbio, Italy, three intervals of elevated 3He concentration were detected: K1 in the Campanian stage at \u223c79 Ma, K2 in the Santonian stage at \u223c85 Ma, and K3 in the Turonian stage at \u223c91 Ma. All three of these episodes are associated with high ^(3)He/^(4)He and ^(3)He/non-carbonate ratios, consistent with their derivation from an enhanced extraterrestrial ^(3)He flux rather than decreased carbonate sedimentation or dissolution. While K2 is modest in magnitude and duration and thus is of limited significance, K1 and K3 are each identified by a few myr interval with an \u223c4-fold enhancement in mean 3He flux compared with pre-event levels. Samples from ODP Hole 762C in the Indian Ocean spanning both K2 and K3 (93\u201383 Ma) confirm the presence of a peak in the Turonian stage, suggesting that K3 is a global event. The K1 and K3 3He events are similar in most respects to the two peaks previously detected in the Cenozoic, suggesting a similar origin. These have been attributed to a major asteroid collision in the Late Miocene and to a shower of either comets or asteroids in the Late Eocene. Based on the age and temporal evolution of K1, we suggest that it most likely records the collision which produced the Baptistina asteroid family independently dated at \u223c80 Ma. The K3 event is less easily explained. It is characterized by an unusually spiky and erratic temporal progression, suggesting an unusual abundance of very ^(3)He rich particles not previously seen in the sedimentary ^(3)He record. We suggest this episode arises either from a comet shower or from an asteroid shower possibly associated with dust-producing lunar impacts.", "date": "2012-05-01", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "84", "publisher": "Elsevier", "pagerange": "314-328", "id_number": "CaltechAUTHORS:20120508-163309947", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120508-163309947", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OCE-1060877" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2012.01.015", "resource_type": "article", "pub_year": "2012", "author_list": "Farley, K. A.; Montanari, A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/92rgx-jhd39", "eprint_id": 31825, "eprint_status": "archive", "datestamp": "2023-08-22 05:34:05", "lastmod": "2023-10-17 21:22:32", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "David L." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Vasconcelos-P-M", "name": { "family": "Vasconcelos", "given": "Paulo M." } }, { "id": "Balco-G", "name": { "family": "Balco", "given": "Greg" } }, { "id": "Monteiro-H-S", "name": { "family": "Monteiro", "given": "Hevelyn S." }, "orcid": "0000-0002-3797-1869" }, { "id": "Waltenberg-K", "name": { "family": "Waltenberg", "given": "Kathryn" } }, { "id": "Stone-J-O", "name": { "family": "Stone", "given": "John O." } } ] }, "title": "Cosmogenic ^(3)He in hematite and goethite from Brazilian \"canga\" duricrust demonstrates the extreme stability of these surfaces", "ispublished": "pub", "full_text_status": "restricted", "keywords": "cosmogenic nuclide geochronology; 3He; 21Ne; laterite; chemical weathering; production rate calibration", "note": "\u00a9 2012 Elsevier B.V. \n\nReceived 1 November 2011. Revised 9 February 2012. Accepted 17 February 2012. Available online 21 March 2012. Editor: B. Marty. \n\nWe thank Vale S.A. for providing us access to the sampling sites at Caraj\u00e1s, Carlos Spier (then at MBR) for providing access and field support for sampling that the Pico Mine, and M. Honda and P.-H. Blard for constructive reviews of the manuscript. Funding was provided by the following sources: UQ-AGES for funding the field sampling exercises at Caraj\u00e1s and Pico, grants NSF- EAR-0738474 (to DLS) and NSF- EAR-0921295 (to KAF), and the Ann and Gordon Getty Foundation.", "abstract": "Helium isotopes were measured in hematite and goethite samples from several lateritiric duricrusts (canga) developed on banded iron formations. These samples uniformly have high ^(3)He concentrations which must arise from long periods of cosmic ray exposure. From coexisting phases from the Quadril\u00e1tero Ferr\u00edfero in east central Brazil, we determined the ratio of cosmogenic ^(3)He in hematite to that of ^(21)Ne in quartz to be 3.96 \u00b1 0.19. Combined with best current estimates of the ^(21)Ne production rate in quartz, this ratio implies a sea-level high latitude (SLHL) ^(3)He production rate in hematite of 68.1 \u00b1 8.1 atoms/g/yr; from the chemical composition we estimate the ^(3)He production rate in goethite to be ~5% higher. We use these production rate estimates to interpret ^(3)He concentrations measured in goethite and hematite from a ~10 m depth profile collected from a surface canga in Caraj\u00e1s, in the Amazon basin of Brazil. We find that the Caraj\u00e1s canga has experienced a very low rate of surface erosion (~0.16\u20130.54 m/Myr) over at least the last few millions of years. This iron-rich canga surface is remarkably resistant to erosion despite its location in a wet tropical environment. Details of the depth profile suggest that despite its stability, the canga has also been internally dynamic (translocation of material; solution and reprecipitation) over million-year timescales.", "date": "2012-05", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "Elsevier", "number": "329-330", "publisher": "Elsevier", "pagerange": "41-50", "id_number": "CaltechAUTHORS:20120606-110644084", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120606-110644084", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "UQ-AGES" }, { "agency": "NSF", "grant_number": "EAR-0738474" }, { "agency": "NSF", "grant_number": "EAR- 0921295" }, { "agency": "Ann and Gordon Getty Foundation" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2012.02.017", "resource_type": "article", "pub_year": "2012", "author_list": "Shuster, David L.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/mtj3w-bgf73", "eprint_id": 30236, "eprint_status": "archive", "datestamp": "2023-08-22 04:57:26", "lastmod": "2023-10-17 15:34:44", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Cox-S-E", "name": { "family": "Cox", "given": "Stephen E." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Hemming-S-R", "name": { "family": "Hemming", "given": "Sidney R." } } ] }, "title": "Insights into the age of the Mono Lake Excursion and magmatic crystal residence time from (U-Th)/He and ^(230)Th dating of volcanic allanite", "ispublished": "pub", "full_text_status": "restricted", "keywords": "allanite; Mono Lake Excursion; Laschamp Excursion; (U-Th)/He; residence time; Wilson Creek", "note": "\u00a9 2011 Elsevier B.V. All rights reserved. Received 31 August 2011. Revised 13 December 2011. Accepted 15 December 2011. Available online 20 January 2012. Editor: B. Marty. We thank Gary Hemming and Guleed Ali for help with sampling\nand logistics, Lindsey Hedges and Adam Subhas for help with chemistry\nand analysis, and Becky Rudolph for assistance with the SEM. This\nresearch was supported by the Columbia Climate Center and the\nComer Foundation, and by the National Science Foundation through\na Graduate Research Fellowship to S. E. Cox.", "abstract": "We present new data for the age of the Mono Lake Excursion at its type locality. Using the (U-Th)/He system on allanite, we dated Wilson Creek Ash 15 (Lajoie, 1968) to 38.7 \u00b1 1.2 ka (2 SE). The new age for this ash supports the hypothesis (Kent et al., 2002; Zimmerman et al., 2006) that the Mono Lake Excursion is coincident with, and probably the same event as, the Laschamp Geomagnetic Excursion (40.4 \u00b1 2 ka), an event that shares similar magnetic characteristics with the excursion identified at Mono Lake. We also estimate an allanite magma residence time of slightly less than 30 ka based on ^(230)Th/^(238)U disequilibrium and the (U-Th)/He-based eruption age.", "date": "2012-02-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "319", "publisher": "Elsevier", "pagerange": "178-184", "id_number": "CaltechAUTHORS:20120420-133514957", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120420-133514957", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Columbia Climate Center" }, { "agency": "Comer Foundation" }, { "agency": "NSF Graduate Research Fellowship" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2011.12.025", "resource_type": "article", "pub_year": "2012", "author_list": "Cox, Stephen E.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/7qcs3-bem82", "eprint_id": 30094, "eprint_status": "archive", "datestamp": "2023-08-22 04:40:56", "lastmod": "2023-10-17 15:22:13", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Amidon-W-H", "name": { "family": "Amidon", "given": "William H." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Cosmogenic ^3He and ^(21)Ne dating of biotite and hornblende", "ispublished": "pub", "full_text_status": "restricted", "keywords": "lithium; fluorine; neon; helium; Bolivia", "note": "\u00a9 2011 Elsevier B.V. \nReceived 19 August 2011. Received in revised form 4 November 2011. Accepted 7 November 2011. Available online 6 December 2011. Received 19 August 2011. Revised 4 November 2011. Accepted 7 November 2011. Available online 6 December 2011. Editor: R.W. Carlson. We thank Julie Libarkin for obtaining and providing samples of the ignimbrite drill core. Thanks to three anonymous reviewers whose comments helped to clarify and improve the manuscript. This work was supported by the National Science Foundation, grant number EAR-0921295.", "abstract": "Stable cosmogenic isotopes such as ^3He and ^(21)Ne are useful for dating of diverse lithologies, quantifying erosion rates and ages of ancient surfaces and sediments, and for assessing complex burial histories. Although many minerals are potentially suitable targets for ^3He and ^(21)Ne dating, complex production systematics require calibration of each mineral\u2013isotope pair. We present new results from a drill core in a high-elevation ignimbrite surface, which demonstrates that cosmogenic ^3He and ^(21)Ne can be readily measured in biotite and hornblende. ^(21)Ne production rates in hornblende and biotite are similar, and are higher than that in quartz due to production from light elements such as Mg and Al. We measure ^(21)Ne_(hbl)/^(21)Ne_(qtz) = 1.35 \u00b1 0.03 and ^(21)Ne_(bio)/^(21)Ne_(qtz) = 1.3 \u00b1 0.02, which yield production rates of 25.6 \u00b1 3.0 and 24.7 \u00b1 2.9 at g^(\u22121) yr^(\u22121) relative to a ^(21)Ne_(qtz) production rate of 19.0 \u00b1 1.8 at g^(\u22121) yr^(\u22121). We show that nucleogenic ^(21)Ne concentrations produced via the reaction ^(18)O(\u03b1,n)^(21)Ne are manageably small in this setting, and we present a new approach to deconvolve nucleogenic ^(21)Ne by comparison to nucleogenic ^(22)Ne produced from the reaction ^(19)F(\u03b1,n)^(22)Ne in F-rich phases such as biotite. Our results show that hornblende is a suitable target phase for cosmogenic ^3He dating, but that ^3He is lost from biotite at Earth surface temperatures. Comparison of ^3He concentrations in hornblende with previously measured mineral phases such as apatite and zircon provides unambiguous evidence for ^3He production via the reaction ^6Li(n,\u03b1)^3H \u2192 ^3He. Due to the atypically high Li content in the hornblende (~ 160 ppm) we estimate that Li-produced ^3He represents ~ 40% of total ^3He production in our samples, and must be considered on a sample-specific basis if 3He dating in hornblende is to be widely implemented.", "date": "2012-01-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "313-314", "publisher": "Elsevier", "pagerange": "86-94", "id_number": "CaltechAUTHORS:20120416-090156503", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120416-090156503", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0921295" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2011.11.005", "resource_type": "article", "pub_year": "2012", "author_list": "Amidon, William H. and Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/gjsp0-m9508", "eprint_id": 24984, "eprint_status": "archive", "datestamp": "2023-08-22 03:26:26", "lastmod": "2023-10-24 15:31:02", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "D. L." } }, { "id": "Ketcham-R-A", "name": { "family": "Ketcham", "given": "R. A." } } ] }, "title": "U and Th zonation in apatite observed by laser ablation ICPMS, and implications for the (U\u2013Th)/He system", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2011 Elsevier Ltd.\n\nReceived 26 January 2011; accepted in revised form 13 May 2011; available online 25 May 2011.\n\nThis work was supported by NSF Grants EAR-0738627 and\nEAR-0738474. D.L.S. acknowledges support from the Ann and Gordon Getty Foundation. We thank Mike Scott for his donation of the LA-ICPMS to Caltech and Yashna Peerthum for analytical assistance.", "abstract": "A laser-ablation inductively-coupled plasma mass spectrometry technique was developed to measure U, Th, and Ce zonation in polished sections of apatite for assessing the consequences of parent zonation for (U\u2013Th)/He thermochronometry. The technique produces concentration maps with an averaging length-scale of ~20 \u03bcm, comparable to the \u03b1-stopping distance, and a precision of ~5% down to few ppm concentration levels. A model was developed to transform the measured concentration distribution into a simplified representation for use in spherical-geometry He production\u2013diffusion models. To illustrate these methods, 30 sections of apatite from a single granite (GC863) were mapped. Every analyzed apatite from GC863 is zoned, with most grains having variable thickness rims and terminations that are enriched in U and Th by about a factor of three over the grain cores.\n\nParent zonation has three independent effects on (U\u2013Th)/He He ages: it influences the \u03b1 ejection correction, the ^(4)He concentration profile which governs diffusive loss, and, via radiation damage trap accumulation, spatial variability of diffusivity within the crystal. If the observed zonation is typical of the apatite population in GC863, use of the standard homogenous \u03b1 ejection correction would cause He ages to be on average 3% too young, and with a large amount of grain-to-grain variability (9% too young in the most rim-enriched case to 6% too old in a core-enriched case). Independent of the ejection correction, the concentration profile modifies the effective closure temperature of the apatites by placing more (or less) ^(4)He near the grain edge. The parent zonation in GC863 apatites causes closure temperatures to range from four degrees lower (rim-enriched case) to two degrees higher (core-enriched case) than applies in the homogenous case. Alpha ejection and concentration profile effects on He age are additive and of the same sense. In the case of typical grains in GC863 cooled between 1 and 10 \u00b0C/Ma, the two effects are roughly equal in magnitude. The effects of intracrystalline variations in radiation damage trap accumulation become apparent at slow cooling rates (1 \u00b0C/Ma). For example, in rim-enriched GC863 grains cooled at 1 \u00b0C/Ma, preferential accumulation of radiation damage traps near the grain rim almost compensates for the higher loss rate expected of 4He also located preferentially near the rim. Under some circumstances strong rim-enrichment may actually increase the effective closure temperature of an apatite. Zonation at the level observed in GC863 modifies the ^(4)He/^(3)He spectra substantially from that expected from a uniform distribution. Measured ^(4)He/^(3)He spectra are strikingly similar to predictions based on the mapped eU distributions of the very same crystals, supporting the overall validity of the analytical and interpretive approach presented here.\n\nThe magnitude and style of U, Th zonation documented in GC863 is one possible source of frequently observed over-dispersion of apatite (U\u2013Th)/He ages as well as anomalous ^(4)He/^(3)He spectra.", "date": "2011-08-15", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "75", "number": "16", "publisher": "Elsevier", "pagerange": "4515-4530", "id_number": "CaltechAUTHORS:20110822-140542688", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110822-140542688", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0738627" }, { "agency": "NSF", "grant_number": "EAR-0738474" }, { "agency": "Ann and Gordon Getty Foundation" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2011.05.020", "resource_type": "article", "pub_year": "2011", "author_list": "Farley, K. A.; Shuster, D. L.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/h5mfw-tf433", "eprint_id": 23283, "eprint_status": "archive", "datestamp": "2023-08-22 02:19:55", "lastmod": "2023-10-23 18:58:45", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lease-R-O", "name": { "family": "Lease", "given": "Richard O." }, "orcid": "0000-0003-2582-8966" }, { "id": "Burbank-W", "name": { "family": "Burbank", "given": "Douglas W." } }, { "id": "Clark-M-K", "name": { "family": "Clark", "given": "Marin K." }, "orcid": "0000-0002-6141-8422" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Zheng-D", "name": { "family": "Zheng", "given": "Dewen" } }, { "id": "Zhang-H", "name": { "family": "Zhang", "given": "Huiping" } } ] }, "title": "Middle Miocene reorganization of deformation along the\n northeastern Tibetan Plateau", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2011 Geological Society of America.\n\nReceived 2 May 2010; Revision received 28 October 2010; Accepted 12 November 2010.\nFirst published online March 8, 2011.\nThis work was supported by the U.S. National Science Foundation (NSF) Continental Dynamics program (grant EAR-0507431), a NSF graduate research fellowship to Lease, and the Chinese National Science Foundation (40234040, 40702028). We thank L. Hedges, P. O'Sullivan, and P. Zhang for assistance, plus E. Cowgill and an anonymous reviewer.", "abstract": "Temporal variations in the orientation of Cenozoic range growth in northeastern Tibet define two modes by which India-Asia convergence was accommodated. Thermochronological\nage-elevation transects from the hanging walls of two major thrust-fault systems reveal diachronous Miocene exhumation of the Laji-Jishi Shan in northeastern Tibet. Whereas\naccelerated growth of the WNW-trending eastern Laji Shan began ca. 22 Ma, rapid growth of the adjacent, north-trending Jishi Shan did not commence until ca. 13 Ma. This change in thrust-fault orientation refl ects a Middle Miocene change in the kinematic style of plateau growth, from long-standing NNE-SSW contraction that mimicked the plate convergence direction to the inclusion of new structures accommodating east-west motion. This kinematic\nshift in northeastern Tibet coincides with expansion of the plateau margin in southeastern Tibet, the onset of normal faulting in central Tibet, and accelerated shortening in northern Tibet. Together these phenomena suggest a plateau-wide reorganization of deformation.", "date": "2011-04", "date_type": "published", "publication": "Geology", "volume": "39", "number": "4", "publisher": "Geological Society of America", "pagerange": "359-362", "id_number": "CaltechAUTHORS:20110412-115452319", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110412-115452319", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0507431" }, { "agency": "NSF Graduate Research Fellowship" }, { "agency": "Chinese National Science Foundation", "grant_number": "40234040" }, { "agency": "Chinese National Science Foundation", "grant_number": "40702028" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/G31356.1", "resource_type": "article", "pub_year": "2011", "author_list": "Lease, Richard O.; Burbank, Douglas W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/6g7nc-6bv19", "eprint_id": 64928, "eprint_status": "archive", "datestamp": "2023-08-19 05:45:49", "lastmod": "2024-01-13 16:42:58", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hurowitz-J-A", "name": { "family": "Hurowitz", "given": "J." }, "orcid": "0000-0002-5857-8652" }, { "id": "Aharonson-O", "name": { "family": "Aharonson", "given": "O." }, "orcid": "0000-0001-9930-2495" }, { "id": "Channon-M-B", "name": { "family": "Channon", "given": "M." } }, { "id": "Chemtob-S-M", "name": { "family": "Chemtob", "given": "S." } }, { "id": "Coleman-M-L", "name": { "family": "Coleman", "given": "M." } }, { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "J." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Grotzinger-J-P", "name": { "family": "Grotzinger", "given": "J. P." }, "orcid": "0000-0001-9324-1257" }, { "id": "Hecht-M-H", "name": { "family": "Hecht", "given": "M." } }, { "id": "Kirschvink-J-L", "name": { "family": "Kirschvink", "given": "J. L." }, "orcid": "0000-0001-9486-6689" }, { "id": "McLeese-D", "name": { "family": "McLeese", "given": "D." } }, { "id": "Neidholdt-E-L", "name": { "family": "Neidholdt", "given": "E." } }, { "id": "Rossman-G-R", "name": { "family": "Rossman", "given": "G. R." }, "orcid": "0000-0002-4571-6884" }, { "id": "Sinha-M-P", "name": { "family": "Sinha", "given": "M." } }, { "id": "Sturhahn-W", "name": { "family": "Sturhahn", "given": "W." }, "orcid": "0000-0002-9606-4740" }, { "id": "Waltenberg-K", "name": { "family": "Waltenberg", "given": "K." } }, { "id": "Vasconcelos-P-M", "name": { "family": "Vasconcelos", "given": "P." } }, { "id": "Zimmermann-W-Jr", "name": { "family": "Zimmermann", "given": "W." } }, { "id": "Beard-B-L", "name": { "family": "Beard", "given": "B." } }, { "id": "Johnson-C", "name": { "family": "Johnson", "given": "C." } } ] }, "title": "In-Situ K-Ar Geochronology: Age Dating for Solar System Sample Return Selection", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 Universities Space Research Association.\n\nPublished - K-Ar.pdf
", "abstract": "The development of an in-situ\ngeochronology capability for Mars and other planetary\nsurfaces has the potential to fundamentally change our\nunderstanding of the evolution of terrestrial bodies in\nthe Solar System. For Mars specifically, many of our\nmost basic scientific questions about the geologic history\nof the planet require accurate knowledge of the\nabsolute time at which an event or process took place.\nFor instance, what was the age and rate of early Martian\nclimate change faithfully recorded in the mineralogy\nand morphology of surface lithologies (e.g., [1])?\nCurrently, our only means of assessing the absolute\nage of a surface on a planetary body is through the use\nof crater counting statistics. This technique is fraught\nwith uncertainty for planets with active geologic surfaces,\non the order of billions of years in some cases\n(e.g., [2]). Accordingly, there is much room for improvement\nin our understanding of the absolute chronology\nof the surfaces of rocky planetary bodies.", "date": "2011-03", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20160301-141416249", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160301-141416249", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "1611", "name": "LPI Contribution" } ] }, "local_group": { "items": [ { "id": "Keck-Institute-for-Space-Studies" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "K-Ar.pdf", "url": "https://authors.library.caltech.edu/records/6g7nc-6bv19/files/K-Ar.pdf" }, "resource_type": "conference_item", "pub_year": "2011", "author_list": "Hurowitz, J.; Aharonson, O.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/x8c1h-bv838", "eprint_id": 21970, "eprint_status": "archive", "datestamp": "2023-08-22 01:53:37", "lastmod": "2023-10-23 15:33:43", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Amidon-W-H", "name": { "family": "Amidon", "given": "William H." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Cosmogenic ^3He production rates in apatite, zircon and pyroxene inferred from Bonneville flood erosional surfaces", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Helium; 3H; Tritium; Shoshone Falls; Twin Falls; Li; Thermal neutron", "note": "\u00a9 2010 Elsevier B.V.\nReceived 4 January 2010; revised 24 March 2010; accepted 30 March 2010. Available online 7 April 2010. \n\n\nWe acknowledge funding from NSF grant EAR-0921295 as well\nas field assistance from Kevin Uno and insightful discussions with\nMichael Lamb. Careful reviews by Pete Burnard and Samuel Niedermann\ngreatly improved the manuscript.\n\nEditorial handling by: D. Bourl\u00e8s.", "abstract": "^3He concentrations were measured in zircon, apatite and pyroxene separates from rhyolite surfaces along the Snake River near Twin Falls, Idaho. These fluted and potholed surfaces were presumably scoured by the Bonneville outburst flood ~17.5 ka. Several of the samples contain inherited ^3He from prior exposure, reflecting the complex incision history of the Snake River canyon and suggesting earlier flood events. Each individual mineral from the remaining surfaces yielded ^3He concentrations that are within error of each other. ^3He produced by neutron capture on ^6Li was established from shielded samples and a simple neutron production model. The remaining ^3He is spallogenic and was used to calibrate the production rate of cosmogenic ^3He in zircon, apatite and pyroxene by assuming minimal erosion since the Bonneville flood. In all three phases the resulting production rates are ~7\u201312% lower than previous ^3He production rate estimates obtained by reference to various production rates for ^(10)Be in quartz. This disagreement is partially reconciled here by recalculating previous results with a ^(10)Be production rate of 4.51 at g^(\u22121) a^(\u22121) in quartz. Adopting this revised rate brings three independent ^3He production rate estimates for zircon and apatite into agreement within 5%, with grand means of 103 \u00b1 3 at g^(\u22121) a^(\u22121) in zircon and 133 \u00b1 6 at g^(\u22121) a^(\u22121) in apatite. The major source of uncertainty in cosmogenic ^3He dating of these phases is now correction for ^3He produced by neutron capture on ^6Li. Calculations are presented for assessing the amount of uncertainty introduced by this correction as a function of Li concentration, cosmic-ray exposure age, and He closure age.", "date": "2011-02", "date_type": "published", "publication": "Quaternary Geochronology", "volume": "6", "number": "1", "publisher": "Elsevier", "pagerange": "10-21", "id_number": "CaltechAUTHORS:20110202-120311957", "issn": "1871-1014", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110202-120311957", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0921295" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.quageo.2010.03.005", "resource_type": "article", "pub_year": "2011", "author_list": "Amidon, William H. and Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/d2k9v-dcf85", "eprint_id": 21670, "eprint_status": "archive", "datestamp": "2023-08-22 01:28:44", "lastmod": "2023-10-21 00:13:33", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zheng-Dewen", "name": { "family": "Zheng", "given": "Dewen" } }, { "id": "Clark-M-K", "name": { "family": "Clark", "given": "Marin K." }, "orcid": "0000-0002-6141-8422" }, { "id": "Zhang-Peizhen", "name": { "family": "Zhang", "given": "Peizhen" } }, { "id": "Zheng-Wenjun", "name": { "family": "Zheng", "given": "Wenjun" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Erosion, fault initiation and topographic growth of the North Qilian Shan (northern Tibetan Plateau)", "ispublished": "pub", "full_text_status": "restricted", "keywords": "(U-Th)/He; absolute age; apatite; Asia; Cenozoic; China; compression tectonics; cooling; elevation; erosion; exhumation; Far East; faults; granites; igneous rocks; northeastern Tibetan Plateau; orogeny; phosphates; plutonic rocks; Qilian Mountains; slip rates; tectonics; thermal history; Tibetan Plateau; topography", "note": "\u00a9 2010 Geological Society of America.\n\nReceived 12 May 2009. \nRevision received 9 April 2010. \nAccepted 11 May 2010. \n\n\nFirst published online October 22, 2010.\n\nWe thank Lindsey Hedges, Alison Duvall, Peter\nMolnar, and support by the National Science Foundation\nof China (40672134 and 40234040), and\nDFIGCEA0607122, and the US National Science\nFoundation, Continental Dynamics Program (EAR-\n0507431). Reviews by G. Dupont-Nivet, A. Carter, K.\nHuntington, and three anonymous reviewers improved\nthe clarity of this manuscript.", "abstract": "New apatite (U-Th)/He from the northeastern\nmargin of the Tibetan Plateau (north\nQilian Shan) indicate rapid cooling began at\n~10 Ma, which is attributed to the onset of\nfaulting and topographic growth. Preservation\nof the paleo-PRZ in the hanging wall and\ngrowth strata in the footwall allow us to calculate\nvertical and horizontal fault slip rates\naveraged over the last 10 Myr of ~0.5 mm/yr\nand ~1 mm/yr respectively, which are within\na factor of two consistent with Holocene slip\nrates and geodetic data. Low fault slip rates\nsince the initiation of the northern Qilian\nShan fault suggest that total horizontal offset\ndid not exceed 10 km. Further, emergence\nof the northern Qilian Shan occurs during\na period of increased aridity in northern\nTibet but is associated with only a minor\nexpansion of the northern plateau perimeter,\nwhich is well established near collision\ntime. Outgrowth of the northern Qilian Shan\nat ~10 Ma could be simple propagation of\nthe larger Qilian Shan system, occurring in\nresponse to decreased slip rates on the Altyn\nTagh fault or as a result of the change in GPE\nof the central plateau.", "date": "2010-12", "date_type": "published", "publication": "Geosphere", "volume": "6", "number": "6", "publisher": "Geological Society of America", "pagerange": "937-941", "id_number": "CaltechAUTHORS:20110110-113846518", "issn": "1553-040X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110110-113846518", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Science Foundation of China", "grant_number": "40672134" }, { "agency": "National Science Foundation of China", "grant_number": "40234040" }, { "agency": "National Science Foundation of China", "grant_number": "DFIGCEA0607122" }, { "agency": "NSF", "grant_number": "EAR-0507431" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/GES00523.1", "resource_type": "article", "pub_year": "2010", "author_list": "Zheng, Dewen; Clark, Marin K.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/s6h8e-mxj09", "eprint_id": 21528, "eprint_status": "archive", "datestamp": "2023-08-22 01:06:47", "lastmod": "2023-10-21 00:06:34", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Amidon-W-H", "name": { "family": "Amidon", "given": "William H." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Mass spectrometric ^3He measurement in ^4He-rich phases: Techniques and limitations for cosmogenic ^3He dating of zircon, apatite, and titanite", "ispublished": "pub", "full_text_status": "public", "keywords": "helium; MAP 215-50; abundance sensitivity; noble gas; sensitivity", "note": "\u00a9 2010 American Geophysical Union.\n\nReceived 14 April 2010; accepted 29 July 2010; published 8 October 2010. \n\n\nThis manuscript benefited greatly from reviews by Rainer\nWieler and two anonymous reviewers. This work was supported\nby NSF\u2010EAR 0921295.\n\nPublished - Amidon2010p12305Geochem_Geophy_Geosy.pdf
", "abstract": "Recent calibration studies have expanded the range of target minerals suitable for cosmogenic ^3He dating to include U and Th-rich phases such as zircon, apatite, and titanite. These minerals often contain large amounts of radiogenic ^4He that present several analytical challenges for precise and accurate ^3He determinations. In this paper we document the abundance sensitivity and changes in the absolute sensitivity and time evolution of the ^3He signal over a wide range of ^4He pressures in a MAP 215-50 noble gas mass spectrometer. Large (>50%) decreases in sensitivity with ^4He amount arising from space charge effects were observed but can be corrected for using an isotope dilution\u2013like technique in which ^3He spike is added to a sample midway through the mass spectrometric analysis. Large amounts of ^4He also cause the time evolution of the ^3He signal to become steeper, degrading precision of the initial peak height determination from the intercept. Taken together we find that these effects preclude reliable analysis of samples with ^4He > 1 \u03bcmol and that ^3He/^4He ratios of greater than ~5 \u00d7 10^(\u221210) are required to routinely measure ^3He to better than 20% precision. We present some general considerations by which to assess the probability of success of measuring cosmogenic ^3He in these phases as a function of elevation, exposure age, and helium cooling age.", "date": "2010-10-08", "date_type": "published", "publication": "Geochemistry, Geophysics, Geosystems", "volume": "11", "number": "10", "publisher": "American Geophysical Union", "pagerange": "Art. No. Q10004", "id_number": "CaltechAUTHORS:20110103-094612966", "issn": "1525-2027", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110103-094612966", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0921295" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2010GC003178", "primary_object": { "basename": "Amidon2010p12305Geochem_Geophy_Geosy.pdf", "url": "https://authors.library.caltech.edu/records/s6h8e-mxj09/files/Amidon2010p12305Geochem_Geophy_Geosy.pdf" }, "resource_type": "article", "pub_year": "2010", "author_list": "Amidon, William H. and Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/hersc-qna51", "eprint_id": 22697, "eprint_status": "archive", "datestamp": "2023-08-22 01:06:15", "lastmod": "2023-10-23 17:08:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "D. L." } }, { "id": "Watson-E-B", "name": { "family": "Watson", "given": "E. B." } }, { "id": "Wanser-K-H", "name": { "family": "Wanser", "given": "K. H." } }, { "id": "Balco-G", "name": { "family": "Balco", "given": "G." } } ] }, "title": "Numerical investigations of apatite ^4He/^3He thermochronometry", "ispublished": "pub", "full_text_status": "public", "keywords": "geochronology; He dating; He-4/He-3", "note": "\u00a9 2010 American Geophysical Union.\nReceived 27 May 2010; accepted 18 August 2010; published 6 October 2010. \n\nThis work was supported by NSF grants to K.A.F. (EAR\u2010\n0738627), D.L.S. (EAR\u20100738474), and E.B.W. (EAR\u2010\n0440228 and EAR\u20100738843). D.L.S. also acknowledges the\nAnn and Gordon Getty Foundation.\n\nPublished - Farley2010p12822Geochem_Geophy_Geosy.pdf
Supplemental Material - 2010gc003243-ds01.txt
Supplemental Material - 2010gc003243-ds02.txt
Supplemental Material - 2010gc003243-ds03.txt
Supplemental Material - 2010gc003243-ds04.txt
Supplemental Material - 2010gc003243-ds05.txt
Supplemental Material - 2010gc003243-ds06.txt
", "abstract": "Apatite ^4He/^3He thermochronometry has the potential to constrain cooling histories for individual samples provided that several presently untested assumptions are valid. Here we simulate the sensitivity of ^4He/^3He spectra to assumptions regarding geometric model, crystallographic anisotropy, broken grain terminations, parent nuclide zonation, and the accuracy of results obtained from analyses of aggregates of multiple crystals. We find that ^4He/^3He spectra obtained from a cylinder with isotropic diffusion are almost indistinguishable from those obtained from an equivalent sphere with an equivalent initial ^4He distribution. Under similar conditions anisotropic diffusion from the cylinder can greatly bias ^4He/^3He spectra, but only if diffusion is >10 times faster in the axial than the radial direction. Existing data argue against anisotropy of this magnitude. We find that analysis of apatites with broken terminations will also bias ^4He/^3He spectra, but not greatly so. In contrast, we find that zonation of a factor of 3 in parent nuclide concentration produces ^4He/^3He spectra that deviate substantially from the homogeneous model. When parent nuclides are highly concentrated near the grain rim and/or cooling is fast, the resulting ^4He/^3He spectra will be readily identified as aberrant. However, more subtle zonation, higher concentrations in the grain interior, or samples that have cooled slowly regardless of zonation style can yield ^4He/^3He spectra that look acceptable but will lead to inaccurate thermochronometric interpretation if parent homogeneity is assumed. Finally, we find that analysis of an aggregate of crystals with identical ^4He distributions can yield ^4He/^3He spectra (and diffusion Arrhenius arrays) that are very different from those that would be obtained on the individual crystals if even small variations in He diffusion exist among the grains. Overall, our observations suggest that modeling tools that assume spherical geometry and isotropic diffusion are appropriate for interpreting apatite ^4He/^3He spectra. However, it is essential to analyze only individual crystals and to assess the degree of parent nuclide zonation in those crystals.", "date": "2010-10-06", "date_type": "published", "publication": "Geochemistry, Geophysics, Geosystems", "volume": "11", "number": "10", "publisher": "American Geophysical Union", "pagerange": "Art. No. Q10001", "id_number": "CaltechAUTHORS:20110307-135031219", "issn": "1525-2027", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110307-135031219", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0738627" }, { "agency": "NSF", "grant_number": "EAR-0738474" }, { "agency": "NSF", "grant_number": "EAR-0440228" }, { "agency": "NSF", "grant_number": "EAR-0738843" }, { "agency": "Ann and Gordon Getty Foundation" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2010GC003243", "primary_object": { "basename": "2010gc003243-ds01.txt", "url": "https://authors.library.caltech.edu/records/hersc-qna51/files/2010gc003243-ds01.txt" }, "related_objects": [ { "basename": "2010gc003243-ds02.txt", "url": "https://authors.library.caltech.edu/records/hersc-qna51/files/2010gc003243-ds02.txt" }, { "basename": "2010gc003243-ds03.txt", "url": "https://authors.library.caltech.edu/records/hersc-qna51/files/2010gc003243-ds03.txt" }, { "basename": "2010gc003243-ds04.txt", "url": "https://authors.library.caltech.edu/records/hersc-qna51/files/2010gc003243-ds04.txt" }, { "basename": "2010gc003243-ds05.txt", "url": "https://authors.library.caltech.edu/records/hersc-qna51/files/2010gc003243-ds05.txt" }, { "basename": "2010gc003243-ds06.txt", "url": "https://authors.library.caltech.edu/records/hersc-qna51/files/2010gc003243-ds06.txt" }, { "basename": "Farley2010p12822Geochem_Geophy_Geosy.pdf", "url": "https://authors.library.caltech.edu/records/hersc-qna51/files/Farley2010p12822Geochem_Geophy_Geosy.pdf" } ], "resource_type": "article", "pub_year": "2010", "author_list": "Farley, K. A.; Shuster, D. L.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/8q7m1-2dw45", "eprint_id": 19798, "eprint_status": "archive", "datestamp": "2023-08-22 00:46:58", "lastmod": "2023-10-20 21:54:17", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Murphy-B-H", "name": { "family": "Murphy", "given": "B. H." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Zachos-J-C", "name": { "family": "Zachos", "given": "J. C." } } ] }, "title": "An extraterrestrial ^3He-based timescale for the Paleocene\u2013Eocene thermal maximum (PETM) from Walvis Ridge, IODP Site 1266", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2010 Elsevier. \nReceived 6 July 2009; accepted 26 March 2010. Associate editor: Jitendra N. Goswami. Available online 11 June 2010. \n\n\nThis paper benefited by the comments of by AE J.N. Goswami,\nGreg Ravizza, and Franco Marcantonio during the review process.\nWe thank Margaret Delaney, Jerry Dickens, Paul Koch, Julie Murphy,\nThomas Westerhold, and Richard Zeebe for helpful discussions\nand Ryan Haupt, Lindsey Hedges, and Nadine Periat for\ntheir analytical assistance. This work was supported by National\nScience Foundation Grant EAR-0628719.", "abstract": "In the deep-sea, the Paleocene\u2013Eocene Thermal Maximum (PETM) is often marked by clay-rich condensed intervals caused by dissolution of carbonate sediments, capped by a carbonate-rich interval. Constraining the duration of both the dissolution and subsequent cap-carbonate intervals is essential to computing marine carbon fluxes and thus testing hypotheses for the origin of this event. To this end, we provide new high-resolution helium isotope records spanning the Paleocene\u2013Eocene boundary at ODP Site 1266 in the South Atlantic. The extraterrestrial ^3He, ^3He_(ET), concentrations replicate trends observed at ODP Site 690 by Farley and Eltgroth (2003). By assuming a constant flux of ^3He_(ET) we constrain relative changes in accumulation rates of sediment across the PETM and construct a new age model for the event. In this new chronology the zero carbonate layer represents 35 kyr, some of which reflects clay produced by dissolution of Paleocene (pre-PETM) sediments. Above this layer, carbonate concentrations increase for ~165 kyr and remain higher than in the latest Paleocene until 234 ^(+48)/_(\u221234) kyr above the base of the clay. The new chronology indicates that minimum \u03b4^(13)C values persisted for a maximum of 134 ^(+27)/_(\u221219) kyr and the inflection point previously chosen to designate the end of the CIE recovery occurs at 217 ^(+44)/_(\u221231) kyr. This allocation of time differs from that of the cycle-based age model of R\u00f6hl et al. (2007) in that it assigns more time to the clay layer followed by a more gradual recovery of carbonate-rich sedimentation. The new model also suggests a longer sustained \u03b4^(13)C excursion followed by a more rapid recovery to pre-PETM \u03b4^(13)C values. These differences have important implications for constraining the source(s) of carbon and mechanisms for its subsequent sequestration, favoring models that include a sustained release of carbon after an initial pulse.", "date": "2010-09-01", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "74", "number": "17", "publisher": "Elsevier", "pagerange": "5098-5108", "id_number": "CaltechAUTHORS:20100907-105245009", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100907-105245009", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0628719" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2010.03.039", "resource_type": "article", "pub_year": "2010", "author_list": "Murphy, B. H.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/5psmp-21h47", "eprint_id": 19336, "eprint_status": "archive", "datestamp": "2023-08-23 23:31:52", "lastmod": "2023-10-20 20:34:33", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rusmore-M-E", "name": { "family": "Rusmore", "given": "Margaret E." } }, { "id": "Bogue-S-W", "name": { "family": "Bogue", "given": "Scott W." } }, { "id": "Dodson-K", "name": { "family": "Dodson", "given": "Karen" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Woodsworth-G-J", "name": { "family": "Woodsworth", "given": "Glenn J." } } ] }, "title": "Deformation of continental crust along a transform boundary, Coast Mountains, British Columbia", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2010 by the American Geophysical Union.\n\nReceived 23 March 2009; accepted 2 March 2010; published 17 July 2010. \nThis research was supported by NSF\nawards EAR 0310011, 9805124, and 9807740. We are grateful to all\nwho helped us in the field: Bill Robinson provided excellent logistical support,\nand help from our field assistants Shannon Shula, Juliet Robinson, and\nRon Karpilo was invaluable. Discussions with Carol Evenchick, George\nGehrels, Lincoln Hollister, James Haggart, and Paul Umhoefer have shaped\nour thoughts on this topic over the years. Reviews by Associate Editor Paul\nKapp and Michael Oskin greatly improved the manuscript.\n\nPublished - Rusmore2010p10941Tectonics.pdf
", "abstract": "New structural, paleomagnetic, and apatite (U-Th)/He results from the continental margin inboard of the Queen Charlotte fault (~54\u00b0N) delineate patterns of brittle faulting linked to transform development since ~50 Ma. In the core of the orogen, ~250 km from the transform, north striking, dip-slip brittle faults and vertical axis rotation of large crustal domains occurred after ~50 Ma and before intrusion of mafic dikes at 20 Ma. By 20 Ma, dextral faulting was active in the core of the orogen, but extension had migrated toward the transform, continuing there until <9 Ma. Local tilting in the core of the orogen is associated with glacially driven, post-4 Ma exhumation. Integration with previous results shows that post-50 Ma dextral and normal faulting affected a region ~250 km inboard of the transform and ~300 km along strike. Initially widespread, the zone of active extension narrowed and migrated toward the transform ~25 Ma after initiation of the transform, while dextral faulting continued throughout the region. Differential amounts of post-50 Ma extension created oroclines at the southern and northern boundaries of the deformed region. This region approximately corresponds to continental crust that was highly extended just prior to transform initiation. Variation in Neogene crustal tilts weakens interpretations relying on uniform tilting to explain anomalous paleomagnetic inclinations of mid-Cretaceous plutons. Similarities to the Gulf of California suggest that development of a transform in continental crust is aided by previous crustal extension and that initially widespread extension narrows and moves toward the transform as the margin develops.", "date": "2010-07-17", "date_type": "published", "publication": "Tectonics", "volume": "29", "publisher": "American Geophysical Union", "pagerange": "Art. No. TC4007", "id_number": "CaltechAUTHORS:20100809-094819405", "issn": "0278-7407", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100809-094819405", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR 0310011" }, { "agency": "NSF", "grant_number": "9805124" }, { "agency": "NSF", "grant_number": "9807740" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2009TC002502", "primary_object": { "basename": "Rusmore2010p10941Tectonics.pdf", "url": "https://authors.library.caltech.edu/records/5psmp-21h47/files/Rusmore2010p10941Tectonics.pdf" }, "resource_type": "article", "pub_year": "2010", "author_list": "Rusmore, Margaret E.; Bogue, Scott W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/qndq9-bjr02", "eprint_id": 19290, "eprint_status": "archive", "datestamp": "2023-08-23 23:31:48", "lastmod": "2023-10-20 20:30:47", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clark-M-K", "name": { "family": "Clark", "given": "Marin K." }, "orcid": "0000-0002-6141-8422" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Zheng-Dewen", "name": { "family": "Zheng", "given": "Dewen" } }, { "id": "Wang-Zhicai", "name": { "family": "Wang", "given": "Zhicai" } }, { "id": "Duvall-A-R", "name": { "family": "Duvall", "given": "Alison R." }, "orcid": "0000-0002-7760-7236" } ] }, "title": "Early Cenozoic faulting of the northern Tibetan Plateau margin from apatite (U\u2013Th)/He ages", "ispublished": "pub", "full_text_status": "public", "keywords": "Tibet; Asia; low-temperature thermochronometry; (U-Th)/He dating; faulting; Indo-Asian collision", "note": "\u00a9 2010 Elsevier B.V. \nReceived 3 July 2009; revised 28 April 2010; accepted 30 April 2010. Editor: R.D. van der Hilst. Available online 8 June 2010. \n\nThis work was supported by NSF grants EAR-0507431 (Clark) and\nEAR-0507788 (Farley), Texaco Prize Postdoctoral Fellowship to Clark and National Science Foundation of China (40234040, 40772127) and\nby State Key Laboratory of Earthquake Dynamics (LED2008A01)\n(Zheng and Wang). We thank Lindsey Hedges for sample preparation\nand analyses; Carmala Garzione, Eric Kirby, Peter Molnar, Gerard Roe\nand Dao-Yang Yuan for field assistance; Doug Burbank and Peter\nMolnar for comments; and Todd Ehlers for discussion of sedimentary\nbasin thermal gradients. An anonymous reviewer provided valuable\nfeedback that improved the clarity of the manuscript.\n\nSupplemental Material - f.xls
", "abstract": "Models to explain the distributed nature of continental deformation predict the propagation of strain and high topography away from the plate boundary. Yet a growing body of evidence in the Tibetan orogen suggests that deformation occurred at the far northern extent of the modern plateau early in the orogen's history and thus our current mechanical understanding of orogenic plateau development is incomplete. New apatite (U\u2013Th)/He ages from four elevation transects document periods of rapid exhumation related to erosion pulses in hanging wall rocks of major thrust structures. Accelerated erosion is used as a proxy of fault timing, and is interpreted in a larger context of structural data and sediment accumulation in adjacent foreland basins. Helium results are synthesized with published geologic, thermochronometric, and sedimentologic data from which a growing picture of regional compressional deformation in Middle to Late Eocene time in northern Tibet emerges. We relate the early Cenozoic period of deformation to the initiation of collision between India and Eurasia, despite the fact that the plate boundary was located > 3000 km to the south. Regardless of whether or not high topography was built simultaneously as a result of this deformation, early Cenozoic strain signifies that the modern limit of the orogen has been relatively stationary since continental collision began and that deformation has not significantly propagated farther away from the plate boundary in time.", "date": "2010-07-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "296", "number": "1-2", "publisher": "Elsevier", "pagerange": "78-88", "id_number": "CaltechAUTHORS:20100805-093833242", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100805-093833242", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0507431" }, { "agency": "NSF", "grant_number": "EAR-0507788" }, { "agency": "Texaco Prize Postdoctoral Fellowship" }, { "agency": "National Science Foundation of China", "grant_number": "40234040" }, { "agency": "National Science Foundation of China", "grant_number": "40772127" }, { "agency": "State Key Laboratory of Earthquake Dynamics", "grant_number": "LED2008A01" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2010.04.051", "primary_object": { "basename": "f.xls", "url": "https://authors.library.caltech.edu/records/qndq9-bjr02/files/f.xls" }, "resource_type": "article", "pub_year": "2010", "author_list": "Clark, Marin K.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/j62b6-05j90", "eprint_id": 17341, "eprint_status": "archive", "datestamp": "2023-08-22 00:50:38", "lastmod": "2023-10-19 23:47:28", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Watson-E-B", "name": { "family": "Watson", "given": "E. Bruce" } }, { "id": "Wanser-K-H", "name": { "family": "Wanser", "given": "Keith H." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Anisotropic diffusion in a finite cylinder, with geochemical applications", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2009 Elsevier.\n\nReceived 3 June 2009; accepted 1 October 2009. Associate editor: Peter W. Reiners. Available online 14 October 2009. \n\nThis work was supported by National Science Foundation\nGrants Nos. EAR-0440228 and EAR-0738843 to EBW and\nEAR-0738627 to KAF. We thank Daniele Cherniak for helpful discussion\nand advice. Sumit Chakraborty, Todd Ehlers, Peter Zeitler\nand an anonymous reviewer provided valuable official reviews.", "abstract": "Atomic diffusion in minerals may not be well represented by solutions to the diffusion equation for a sphere with a singlevalued diffusivity, either because they have platy or elongated habits or because the energetics of diffusion is sensitive to crystallographic direction. In many cases, a cylinder having characteristic radial and axial diffusivities is arguably a better model, but rigorous solutions to the anisotropic diffusion equation for a finite cylinder have not been available. Here we develop general analytical solutions that capture both the internal distribution of diffusant as a function of time, C(r, z, t), and the fraction, F, of diffusant lost during a specified thermal history. These solutions are shown to conform with existing analytical expressions for limiting cases of diffusion in a slab or infinite cylinder. We present, in addition, a simple numerical (finite difference)\napproach that not only reproduces the results of our analytical expressions but also enables us to move beyond some of the limitations of the equations to simulate complex natural scenarios involving non-zero and time-dependent boundary conditions, arbitrary initial distribution of diffusant within the cylinder and simultaneous diffusion and radiogenic ingrowth. The complementary nature of the two approaches is emphasized and several illustrative applications to 'real-world' problems are described, including noble-gas thermochronometry and halogen\u2013hydroxyl interdiffusion in apatite.", "date": "2010-01-15", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "74", "number": "2", "publisher": "Elsevier", "pagerange": "614-633", "id_number": "CaltechAUTHORS:20100128-135201520", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100128-135201520", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0440228" }, { "agency": "NSF", "grant_number": "EAR-0738843" }, { "agency": "NSF", "grant_number": "EAR-0738627" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2009.10.013", "resource_type": "article", "pub_year": "2010", "author_list": "Watson, E. Bruce; Wanser, Keith H.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/82mwy-kmy95", "eprint_id": 17054, "eprint_status": "archive", "datestamp": "2023-08-21 22:52:08", "lastmod": "2023-10-19 22:46:18", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mah\u00e9o-G", "name": { "family": "Mah\u00e9o", "given": "Gweltaz" } }, { "id": "Saleeby-J-B", "name": { "family": "Saleeby", "given": "Jason" } }, { "id": "Saleeby-Z", "name": { "family": "Saleeby", "given": "Zorka" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Tectonic control on southern Sierra Nevada topography, California", "ispublished": "pub", "full_text_status": "public", "keywords": "Sierra Nevada; thermochronology; faulting", "note": "\u00a9 2009 American Geophysical Union.\nReceived 11 June 2008; accepted 13 August 2009; published 5 December 2009. \nThis research was supported by NSF grants EAR-0230383 and EAR-0606903 and funds from the Gordon and Betty Moore Foundation. We thank Elisabeth Nadin, Marin Clark, and Janice Gillespie for helpful discussions and assistance in the field and Lindsey Hedges for analytical assistance. Helpful reviews by George Hilley and John Wakabayashi are gratefully acknowledged. G. Maheo benefited from the Lavoisier Post-Doctoral Fellowship. Caltech Tectonics Observatory contribution 85.\n\nPublished - Maheo2009p6627Tectonics.pdf
", "abstract": "In this study we integrate the apatite (U-Th)/He thermochronometric technique with geomorphic, structural, and stratigraphic studies to pursue the origin and evolution of topographic relief related to extensive late Cenozoic faulting in the southern Sierra Nevada. The geomorphology of this region reflects a transition from a vast region to the north characterized by nonequilibrium fluvial modification of a relict low-relief landscape, little affected by internal deformation, to a more complex landscape affected by numerous faults. Regionally, the relict landscape surface is readily resolved by age-elevation relationships of apatite He ages coupled to geomorphology. These relationships can be extended into the study area and used as a structural datum for the resolution of fault offsets and related tilting. On the basis of 63 new apatite He ages and stratigraphic data from proximal parts of the San Joaquin basin we resolve two sets of normal faults oriented approximately N\u2013S and approximately NW. Quaternary west-side-up normal faulting along the N\u2013S Breckenridge\u2013Kern Canyon zone has resulted in a southwest step over from the Owens Valley system in the controlling structure on the regional west tilt of Sierran basement. This zone has also served as a transfer structure partitioning Neogene-Quaternary extension resulting from normal displacements on the NW fault set. This fault system for the most part nucleated along Late Cretaceous structures with late Cenozoic remobilization representing passive extension by oblate flattening as the region rose and stretched in response to the passage of a slab window and the ensuing delamination of the mantle lithosphere from beneath the region.", "date": "2009-12-05", "date_type": "published", "publication": "Tectonics", "volume": "28", "number": "6", "publisher": "American Geophysical Union", "pagerange": "Art. No. TC6006", "id_number": "CaltechAUTHORS:20100104-152739521", "issn": "0278-7407", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100104-152739521", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0230383" }, { "agency": "NSF", "grant_number": "EAR-0606903" }, { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "85", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2008TC002340", "primary_object": { "basename": "Maheo2009p6627Tectonics.pdf", "url": "https://authors.library.caltech.edu/records/82mwy-kmy95/files/Maheo2009p6627Tectonics.pdf" }, "resource_type": "article", "pub_year": "2009", "author_list": "Mah\u00e9o, Gweltaz; Saleeby, Jason; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/8kcqp-pnd13", "eprint_id": 17217, "eprint_status": "archive", "datestamp": "2023-08-22 00:47:11", "lastmod": "2023-10-19 23:39:45", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Blard-P-H", "name": { "family": "Blard", "given": "P.-H." } }, { "id": "Lav\u00e9-J", "name": { "family": "Lav\u00e9", "given": "J." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Fornari-M", "name": { "family": "Fornari", "given": "M." } }, { "id": "Jim\u00e9nez-N", "name": { "family": "Jim\u00e9nez", "given": "N." } }, { "id": "Ramirez-V", "name": { "family": "Ramirez", "given": "V." } } ] }, "title": "Late local glacial maximum in the Central Altiplano triggered by cold and locally-wet conditions during the paleolake Tauca episode (17\u201315 ka, Heinrich 1)", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2009 Elsevier Ltd.\nReceived 8 July 2009; \nrevised 18 September 2009; \naccepted 28 September 2009. \nAvailable online 25 October 2009. Constructive comments by Wallace S. Broecker, Joerg M.\nSchaefer and Ano N. Ymous improved an earlier version of this\nmanuscript. This work was mainly funded by the French INSU\nprogram \"Relief de la Terre\" and by the Caltech Tectonics Observatory.\nIt is part of the Post Doc of P.-H. Blard. The authors thank the\nIRD (Institut de Recherche pour le De\u00b4veloppement) of La Paz,\nBolivia, which provided a precious technical and logistical assistance\nin the field. This is CRPG contribution #2017.", "abstract": "The timing and causes of the last deglaciation in the southern tropical Andes is poorly known. In the Central Altiplano, recent studies have focused on whether this tropical highland was deglaciated before, synchronously or after the global last glacial maximum (~ 21 ka BP). In this study we present a new chronology based on cosmogenic ^3He (^3He_c) dating of moraines on Cerro Tunupa, a volcano that is located in the centre of the now vanished Lake Tauca (19.9\u00b0S, 67.6\u00b0W). These new ^3He_c ages suggest that the Tunupa glaciers remained close to their maximum extent until 15 ka BP, synchronous with the Lake Tauca highstand (17\u201315 ka BP). Glacial retreat and the demise of Lake Tauca seem to have occurred rapidly and synchronously, within dating uncertainties, at ~15 ka BP. We took advantage of the synchronism of these events to combine a glacier model with a lake model in order to reconstruct precipitation and temperature during the Lake Tauca highstand. This new approach indicates that, during the Tauca highstand (17\u201315 ka BP), the centre of the Altiplano was characterized by temperature ~ 6.5 \u00b0C cooler and average precipitation higher by a factor ranging between \u00d71.6 and \u00d73 compared to the present. Cold and wet conditions thus persisted in a significant part of the southern tropical Andes during the Heinrich 1 event (17\u201315 ka BP). This study also demonstrates the extent to which the snowline of glaciers can be affected by local climatic conditions and emphasizes that efforts to draw global climate inferences from glacial extents must also consider local moisture conditions.", "date": "2009-12", "date_type": "published", "publication": "Quaternary Science Reviews", "volume": "28", "number": "27-28", "publisher": "Elsevier", "pagerange": "3414-3427", "id_number": "CaltechAUTHORS:20100119-134535247", "issn": "0277-3791", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100119-134535247", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "French INSU (Institut National des Sciences de l'Univers) program ''Relief de la Terre''" }, { "agency": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.quascirev.2009.09.025", "resource_type": "article", "pub_year": "2009", "author_list": "Blard, P.-H.; Lav\u00e9, J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/z2xjw-bz631", "eprint_id": 14382, "eprint_status": "archive", "datestamp": "2023-08-22 00:30:34", "lastmod": "2023-10-18 16:49:12", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flowers-R-M", "name": { "family": "Flowers", "given": "Rebecca M." } }, { "id": "Ketcham-R-A", "name": { "family": "Ketcham", "given": "Richard A." } }, { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "David L." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Apatite (U-Th)/He thermochronometry using a radiation damage accumulation and annealing model", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2009 Elsevier Ltd.\nReceived 13 October 2008; accepted 21 January 2009. Associate editor: Rainer Wieler. Available online 28 January 2009.\nThis work was supported by National Science Foundation\nGrants EAR-0738627 to K.A.F., EAR-0738474 to D.L.S., and\nEAR-0711451 to R.M.F. D.L.S. acknowledges support from the\nAnn and Gordon Getty Foundation. We thank Ray Donelick for\nsupplying many of the apatite fission-track density measurements that are used in the model calibration. We appreciate helpful reviews by Pete Reiners and an anonymous reviewer.", "abstract": "Helium diffusion from apatite is a sensitive function of the volume fraction of radiation damage to the crystal, a quantity that varies over the lifetime of the apatite. Using recently published laboratory data we develop and investigate a new kinetic model, the radiation damage accumulation and annealing model (RDAAM), that adopts the effective fission-track density as a proxy for accumulated radiation damage. This proxy incorporates creation of crystal damage proportional to \u03b1-production from U and Th decay, and the elimination of that damage governed by the kinetics of fission-track annealing. The RDAAM is a version of the helium trapping model (HeTM; Shuster D. L., Flowers R. M. and Farley K. A. (2006) The influence of natural radiation damage on helium diffusion kinetics in apatite. Earth Planet. Sci. Lett. 249, 148\u2013161), calibrated by helium diffusion data in natural and partially annealed apatites. The chief limitation of the HeTM, now addressed by RDAAM, is its use of He concentration as the radiation damage proxy for circumstances in which radiation damage and He are not accumulated and lost proportionately from the crystal.\n\nBy incorporating the RDAAM into the HeFTy computer program, we explore its implications for apatite (U\u2013Th)/He thermochronometry. We show how (U\u2013Th)/He dates predicted from the model are sensitive to both effective U concentration (eU) and details of the temperature history. The RDAAM predicts an effective He closure temperature of 62\u00b0C for a 28 ppm eU apatite of 60 \u03bcm radius that experienced a 10\u00b0C/Ma monotonic cooling rate; this is 8\u00b0C lower than the 70\u00b0C effective closure temperature predicted using commonly assumed Durango diffusion kinetics. Use of the RDAAM is most important for accurate interpretation of (U\u2013Th)/He data for apatite suites that experienced moderate to slow monotonic cooling (1\u20130.1 \u00b0C/Ma), prolonged residence in the helium partial retention zone, or a duration at temperatures appropriate for radiation damage accumulation followed by reheating and partial helium loss. Under common circumstances the RDAAM predicts (U\u2013Th)/He dates that are older, sometimes much older, than corresponding fission-track dates. Nonlinear positive correlations between apatite (U\u2013Th)/He date and eU in apatites subjected to the same temperature history are a diagnostic signature of the RDAAM for many but not all thermal histories.\n\nObserved date-eU correlations in four different localities can be explained with the RDAAM using geologically reasonable thermal histories consistent with independent fission-track datasets. The existence of date-eU correlations not only supports a radiation damage based kinetic model, but can significantly limit the range of acceptable time-temperature paths that account for the data. In contrast, these datasets are inexplicable using the Durango diffusion model. The RDAAM helps reconcile enigmatic data in which apatite (U\u2013Th)/He dates are older than expected using the Durango model when compared with thermal histories based on apatite fission-track data or other geological constraints. It also has the potential to explain at least some cases in which (U\u2013Th)/He dates are actually older than the corresponding fission-track dates.", "date": "2009-04-15", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "73", "number": "8", "publisher": "Elsevier", "pagerange": "2347-2365", "id_number": "CaltechAUTHORS:20090609-164429781", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090609-164429781", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0738627" }, { "agency": "NSF", "grant_number": "EAR-0711451" }, { "agency": "NSF", "grant_number": "EAR-0738474" }, { "agency": "Ann and Gordon Getty Foundation" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2009.01.015", "resource_type": "article", "pub_year": "2009", "author_list": "Flowers, Rebecca M.; Ketcham, Richard A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/nwtzv-ntv80", "eprint_id": 14618, "eprint_status": "archive", "datestamp": "2023-08-22 00:30:46", "lastmod": "2023-10-18 18:08:59", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Amidon-W-H", "name": { "family": "Amidon", "given": "William H." } }, { "id": "Rood-D-H", "name": { "family": "Rood", "given": "Dylan H." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Cosmogenic ^(3)He and ^(21)Ne production rates calibrated against ^(10)Be in minerals from the Coso volcanic field", "ispublished": "pub", "full_text_status": "restricted", "keywords": "helium; neon; ^(10)Be; lithium; Li", "note": "\u00a9 2009 Elsevier B.V.\nReceived 11 November 2008; revised 16 January 2009; accepted 21 January 2009. Editor: R.W. Carlson. Available online 25 February 2009.\nThanks to Don Burnett, P.H. Blard, and Frank Monastero. Thanks to Samuel Niedermann and an anonymous reviewer for greatly improving this manuscript. This work was supported by National Science Foundation Grant 0511053. \n\nSupplementary data associated with this article can be found, in\nthe online version, at doi:10.1016/j.epsl.2009.01.031.", "abstract": "This study calibrates the production rate of cosmogenic ^(3)He in pyroxene, olivine, garnet, zircon and apatite as well as ^(21)Ne in quartz and pyroxene against the known production rate of ^(10)Be in quartz. The Devil's Kitchen rhyolite from the Coso volcanic field in southeastern California (elev. ~ 1300 m) was chosen for this study due to its young age (~ 610 ka) and diverse mineral assemblage. Based on ^(10)Be, our two rhyolite samples have apparent exposure ages of ~ 49 and 93 ka, indicating substantial erosion after eruption. Combining data from the two samples, we estimate sea level high latitude ^(3)He spallation production rates of 145 \u00b1 11, 141 \u00b1 16, and 144 \u00b1 30 at g^\u22121 a\u2212^1 (2\u03c3) for pyroxene, olivine and spessartine garnet respectively. For zircon and apatite, we estimate apparent 3He spallation production rates of 114 \u00b1 8 and 149 \u00b1 28 at g^\u22121 a^\u22121 (2\u03c3) respectively. The rates for zircon and apatite are reported as apparent production rates because we do not explicitly address the redistribution of spallation produced ^(3)He from adjacent minerals. These estimates quantitatively account for production of ^(3)He from both cosmogenic and radiogenic neutron reactions on ^(6)Li within the analyzed phases and also implanted from nuclear reactions in neighboring minerals; the high U, Th and Li content of this rhyolite provides a particularly rigorous test of this correction. We estimate ^(21)Ne production rates of 17.7 \u00b1 1.6 and 34.1 \u00b1 3.2 at g^\u22121 a^\u22121 (2\u03c3) in quartz and pyroxene (Fe/Mg = 0.7 by mass) respectively. Although high U and Th contents create the potential for significant production of nucleogenic ^(21)Ne, this component is small due to the young eruption age of the rhyolite.", "date": "2009-04-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "280", "number": "1-4", "publisher": "Elsevier", "pagerange": "194-204", "id_number": "CaltechAUTHORS:20090720-122319898", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090720-122319898", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "0511053" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2009.01.031", "resource_type": "article", "pub_year": "2009", "author_list": "Amidon, William H.; Rood, Dylan H.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/fpk0k-fw839", "eprint_id": 13062, "eprint_status": "archive", "datestamp": "2023-08-22 14:09:14", "lastmod": "2023-10-17 21:44:44", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "David L." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "The influence of artificial radiation damage and thermal annealing on helium diffusion kinetics in apatite", "ispublished": "pub", "full_text_status": "public", "note": "Copyright \u00a9 2008 Elsevier. \n\nReceived 15 July 2008; accepted 10 October 2008. Associate editor: Rainer Wieler. Available online 21 October 2008. \n\nWe thank D. Cherniak for providing the synthetic apatite sample, R. Ketcham for guidance on fission track annealing, R. Ewing and R. Fleming for helpful discussion about kerma, S. Reese for access to the neutron energy spectrum and the \u03a6eq, 1MeV, Si calibration for the CLICIT, T. Becker for help with neutron irradiations, and P. Reiners and two anonymous referees for helpful reviews. This work was supported by NSF Grants EAR-0738474 to DLS and EAR-0738627 to KAF and the Ann and Gordon Getty Foundation. \n\nSupplementary data associated with this article can be found, in the online version, at doi:10.1016/j.gca.2008.10.013.", "abstract": "Recent work [Shuster D. L., Flowers R. M. and Farley K. A. (2006) The influence of natural radiation damage on helium diffusion kinetics in apatite. Earth Planet. Sci. Lett. 249(3\u20134), 148\u2013161] revealing a correlation between radiogenic 4He concentration and He diffusivity in natural apatites suggests that helium migration is retarded by radiation-induced damage to the crystal structure. If so, the He diffusion kinetics of an apatite is an evolving function of time and the effective uranium concentration in a cooling sample, a fact which must be considered when interpreting apatite (U\u2013Th)/He ages. Here we report the results of experiments designed to investigate and quantify this phenomenon by determining He diffusivities in apatites after systematically adding or removing radiation damage. \n\nRadiation damage was added to a suite of synthetic and natural apatites by exposure to between 1 and 100 h of neutron irradiation in a nuclear reactor. The samples were then irradiated with a 220 MeV proton beam and the resulting spallogenic 3He used as a diffusant in step-heating diffusion experiments. In every sample, irradiation increased the activation energy (Ea) and the frequency factor (Do/a^2) of diffusion and yielded a higher He closure temperature (Tc) than the starting material. For example, 100 h in the reactor caused the He closure temperature to increase by as much as 36 \u00b0C. For a given neutron fluence the magnitude of increase in closure temperature scales negatively with the initial closure temperature. This is consistent with a logarithmic response in which the neutron damage is additive to the initial damage present. In detail, the irradiations introduce correlated increases in Ea and ln(Do/a^2) that lie on the same array as found in natural apatites. This strongly suggests that neutron-induced damage mimics the damage produced by U and Th decay in natural apatites. \n\nTo investigate the potential consequences of annealing of radiation damage, samples of Durango apatite were heated in vacuum to temperatures up to 550 \u00b0C for between 1 and 350 h. After this treatment the samples were step-heated using the remaining natural 4He as the diffusant. At temperatures above 290 \u00b0C a systematic change in Tc was observed, with values becoming lower with increasing temperature and time. For example, reduction of Tc from the starting value of 71 to ~52 \u00b0C occurred in 1 h at 375 \u00b0C or 10 h at 330 \u00b0C. The observed variations in Tc are strongly correlated with the fission track length reduction predicted from the initial holding time and temperature. Furthermore, like the neutron irradiated apatites, these samples plot on the same Ea \u2212 ln(Do/a2) array as natural samples, suggesting that damage annealing is simply undoing the consequences of damage accumulation in terms of He diffusivity. \n\nTaken together these data provide unequivocal evidence that at these levels, radiation damage acts to retard He diffusion in apatite, and that thermal annealing reverses the process. The data provide support for the previously described radiation damage trapping kinetic model of Shuster et al. (2006) and can be used to define a model which fully accommodates damage production and annealing.", "date": "2009-01-01", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "73", "number": "1", "publisher": "Elsevier", "pagerange": "183-196", "id_number": "CaltechAUTHORS:SHUgca09", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:SHUgca09", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Science Foundation", "grant_number": "EAR-0738474" }, { "agency": "National Science Foundation", "grant_number": "EAR-0738627" }, { "agency": "Ann and Gordon Getty Foundation" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2008.10.013", "resource_type": "article", "pub_year": "2009", "author_list": "Shuster, David L. and Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/dsjbg-e1r76", "eprint_id": 54301, "eprint_status": "archive", "datestamp": "2023-08-22 14:44:40", "lastmod": "2024-01-13 16:14:23", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Late Eocene and late Miocene cosmic dust events: Comet showers, asteroid collisions, or lunar impacts?", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2009 Geological Society of America.\n\nAccepted 16 September 2008.\n\nI would like to thank the conveners of the 2007 Penrose Conference\nat which this work was presented: Alessandro Montanari,\nChristian Koeberl, Fritz Hilgen, and Rodolfo Coccioni. I appreciate\nthe helpful reviews of this manuscript by B. Schmitz and\nI. McDonald.", "abstract": "Two long-lived peaks in extraterrestrial ^3He flux have been identified in the sedimentary record of the Cenozoic Era: at 8.2 Ma (late Miocene) and 35.8 Ma (late Eocene). These peaks document the occurrence of important events in the recent history of the solar system. The timing and temporal evolution of the dust event in the late Miocene as well as the absence of major terrestrial impact craters are consistent with an origin in the catastrophic collision that produced the Veritas asteroid family at this time. In contrast, there is no known asteroid collision corresponding to the late Eocene peak. Instead, the late Eocene event has elements consistent with a comet shower produced by a close stellar encounter. Both the rise time and the fall time of the enhanced dust flux and the occurrence of two major terrestrial impacts at the peak of the event are predicted by considerations of comet shower dynamics. However, debris from one of these impacts has a Cr isotope ratio that appears to exclude a carbonaceous chondrite impactor. If the presumption that comets have a carbonaceous chondrite\u2013like composition is accurate, then an alternative mechanism for the late Eocene event may be required. The recent suggestion of an asteroid shower, where the ^3He-bearing dust resulted from lunar impacts, is one such possibility, but it too fails to account fully for existing observations. The cause of the late Eocene event thus remains uncertain.", "date": "2009", "date_type": "published", "publisher": "Geological Society of America", "place_of_pub": "Boulder, CO", "pagerange": "27-35", "id_number": "CaltechAUTHORS:20150202-124202237", "isbn": "978-0-8137-2452-2", "book_title": "The late Eocene Earth: hothouse, icehouse, and impacts", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150202-124202237", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Koeberl-C", "name": { "family": "Koeberl", "given": "Christian" } }, { "id": "Montanari-A", "name": { "family": "Montanari", "given": "Alessandro" } } ] }, "doi": "10.1130/2009.2452(03)", "resource_type": "book_section", "pub_year": "2009", "author_list": "Farley, K. A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ht437-mq454", "eprint_id": 12938, "eprint_status": "archive", "datestamp": "2023-08-22 13:39:50", "lastmod": "2023-10-17 21:39:10", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Blard-P-H", "name": { "family": "Blard", "given": "P.-H." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "The influence of radiogenic 4He on cosmogenic 3He determinations in volcanic olivine and pyroxene", "ispublished": "pub", "full_text_status": "public", "keywords": "cosmogenic; magmatic; radiogenic; Helium-3; Helium-4; R-factor", "note": "Copyright \u00a9 2008 Elsevier. \n\nReceived 2 May 2008; revised 29 August 2008; accepted 2 September 2008. Available online 22 October 2008. Editor: R.W. Carlson. \n\nConstructive comments by Samuel Niedermann, Joe Licciardi and Rick Carlson helped to improve this article. We thank Joe Licciardi for providing unpublished mineral diameters used in his previous articles as well as L. Hedges for her valuable technical assistance in the Caltech lab. This work is part of the Caltech OK-Earl Post-Doctoral Fellowship of P.-H. Blard.", "abstract": "Accurate determination of cosmogenic 3He concentrations in olivine and pyroxene phenocrysts requires knowledge of the amount of magmatic 3He also in the sample. The magmatic 3He component is commonly estimated by measuring the magmatic 3He/4He ratio and assuming that all 4He is magmatic. However, this approach yields incorrect results if 4He produced by U and Th decay is also present. Here we propose several strategies to account for the presence of radiogenic 4He. The optimal approach depends on whether the helium closure age (Tc) is similar to the exposure age (Te) of the analyzed phenocrysts. (i) When Tc = Te, which applies to uneroded lava flows, the ratio of cosmogenic 3He to radiogenic 4He is constant and the correction for radiogenic helium is independent of time. We provide a simple expression for a correction factor (R) that can be applied in this case. (ii) In the more common case that Tc > Te, it is necessary to obtain an independent constraint on the closure age to estimate the radiogenic correction. In either case a quantitative estimate of the radiogenic 4He production rate is required. Because of the long stopping distance of \u03b1-particles, this production rate depends on the U and Th concentrations of both phenocryst and host, and also on phenocryst grain size. To illustrate the magnitude and uncertainty of the necessary corrections, we compiled U and Th measurements on phenocrysts and whole rock samples of basalts and andesites, supplemented by new measurements on Hawaiian basalts and Altiplano andesites. Our data and models suggest that some published cosmogenic 3He production rate determinations may have underestimated the true production rate by up to 5% because the presence of radiogenic 4He was not recognized. Similarly, a recent study presenting cosmogenic 3He derived erosion rates in > 4 Ma Hawaiian olivines probably overestimates true erosion rates by an order of magnitude or more.", "date": "2008-11-30", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "276", "number": "1-2", "publisher": "Elsevier", "pagerange": "20-29", "id_number": "CaltechAUTHORS:BLAepsl08", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:BLAepsl08", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "O.K. Earl Postdoctoral Fellowship, Caltech" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2008.09.003", "resource_type": "article", "pub_year": "2008", "author_list": "Blard, P.-H. and Farley, K. A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/xkgwt-5fs76", "eprint_id": 39555, "eprint_status": "archive", "datestamp": "2023-08-22 12:25:02", "lastmod": "2023-10-24 16:56:02", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Blard-P-H", "name": { "family": "Blard", "given": "P.-H." } }, { "id": "Lav\u00e9-J", "name": { "family": "Lav\u00e9", "given": "J." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Tripati-A-K", "name": { "family": "Tripati", "given": "A." } }, { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "J. M." } }, { "id": "Sylvestre-F", "name": { "family": "Sylvestre", "given": "F." } }, { "id": "Fornari-M", "name": { "family": "Fornari", "given": "M." } } ] }, "title": "Late glacial paleoclimate of the central Altiplano constrained by cosmogenic ^3He dating and 'clumped-isotope' paleothermometry", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2008 Published by Elsevier Ltd.", "abstract": "The timing and causes of the last deglaciation in the\ntropical Andes are still poorly constrained. Moreover, the\npaleoclimatic conditions that existed in this region during the\npaleolake Tauca highstand between 17 and 15 ka [1, 2] are\nstill uncertain. Here we present new cosmogenic ^3He ages\nfrom glacial landforms of Cerro Tunupa (20\u00b0S) showing that,\nin the central part of the Altiplano, glaciers persisted at their\nmaximum position between 17 and 15 ka, and retreated\nsynchronously with the drop of the paleolake Tauca highstand\nafter 15 ka. This result is different from previous moraine\ndating [3] that indicates an earlier (~34 ka) local glacial\nmaximum in the northern part of Altiplano. This discrepancy\nmost likely reflects spatial variability of past precipitation.\nIndeed, the extent of mountain glaciers is determined both by\ntemperatures and local precipitation.", "date": "2008-07", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "72", "number": "12", "publisher": "Elsevier", "pagerange": "A89", "id_number": "CaltechAUTHORS:20130724-103129058", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130724-103129058", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2008.05.005", "resource_type": "article", "pub_year": "2008", "author_list": "Blard, P.-H.; Lav\u00e9, J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/bmxb5-t4727", "eprint_id": 20781, "eprint_status": "archive", "datestamp": "2023-08-22 11:39:38", "lastmod": "2023-10-20 23:26:35", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flowers-R-M", "name": { "family": "Flowers", "given": "R. M." } }, { "id": "Wernicke-B-P", "name": { "family": "Wernicke", "given": "B. P." }, "orcid": "0000-0002-7659-8358" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Unroofing, incision, and uplift history of the southwestern Colorado Plateau from apatite (U-Th)/He thermochronometry", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Colorado Plateau; (U-Th)/He; Grand Canyon; unroofing; incision; uplift; thermochronometry", "note": "\u00a9 2008 Geological Society of America. \n\nManuscript received 23 March 2007; Revised manuscript received 9 September 2007; Manuscript accepted 17 October 2007. \n\nWe thank Dick Young and Andre Potochnik for insightful discussions and for sharing their extensive knowledge of the geology of the southwestern Colorado Plateau. Sam Bowring and Lee Silver generously provided mineral separates for several samples of Proterozoic basement from the Grand Canyon for which we report data. We thank Karl Karlstrom for the opportunity to collect additional basement samples on the University of New Mexico Grand Canyon River trip. \n \nAssociate Editor Frank Pazzaglia and two anonymous referees provided invaluable advice on improving the presentation of both thermochronometric data and its implications for landscape development in the southwestern plateau region. This research was supported by National Science Foundation grants EAR-0610115 and EAR-0408526 and by the California Institute of Technology Tectonics Observatory.", "abstract": "The source of buoyancy for the uplift of cratonic plateaus is a fundamental question in continental dynamics. The ~1.9 km uplift of the Colorado Plateau since the Late Cretaceous is a prime example of this problem. We used apatite (U-Th)/He thermochronometry (230 analyses; 36 samples) to provide the first single-system, regional-scale proxy for the unroofing history of the southwestern quadrant of the plateau. The results confirm overall southwest to northeast unroofing, from plateau margin to plateau interior. A single phase of unroofing along the plateau margin in Late Cretaceous to Early Tertiary (Sevier- Laramide) time contrasts with multiphase unroofing of the southwestern plateau interior in Early and mid- to Late Tertiary time. The Early Cretaceous was characterized by northeastward tilting and regional erosion, followed by aggradation of \u22651500 m of Upper Cretaceous sediments along the eroded plateau margin. Sevier-Laramide denudation affected the entire southwestern plateau, was concentrated along the plateau margin, and migrated from northwest to southeast. Following a period of relative stability of the landscape from ca. 50\u201330 Ma, significant unroofing of the southwestern plateau interior occurred between ca. 28 and 16 Ma. Additional denudation north of the Grand Canyon took place in latest Tertiary time. Mid-Tertiary dates from the Grand Canyon basement at the bottom of the Upper Granite Gorge limit significant incision of the modern Grand Canyon below the Kaibab surface to <23 Ma. Modeling the age distributions of samples from the basement and Kaibab surface nearby suggests that the gorge and the plateau surface had similar Early to mid-Tertiary thermal histories, despite their >1500 m difference in vertical structural position. If these models are correct, they indicate that a \"proto\u2013Grand Canyon\" of kilometer-scale depth had incised post-Paleozoic strata by the Early Eocene. Evidence for kilometer-scale mid-Tertiary relief in northeast-fl owing drainages along the plateau margin, as well as the mid-Tertiary episode of plateau interior unroofing, imply that the southwestern plateau interior had attained substantial elevation by at least 25\u201320 Ma, if not much earlier. These observations are inconsistent with any model calling for exclusively Late Tertiary uplift of the southwestern plateau. Sevier-Laramide plateau surface uplift and incision thus result from one or more processes that enhanced the buoyancy of the plateau lithosphere, expanding the Cordillera's orogenic highlands into its low-standing cratonic foreland. The onset of the Laramide slab's demise at ca. 40 Ma and the major pulse of extension in the Basin and Range from ca. 16\u201310 Ma appear to have had little influence on the denudation history of the southwestern plateau. In contrast, the post-Laramide unroofing episodes may be explained by drainage adjustments induced by rift-related lowering of regions adjacent to the plateau, without the need to otherwise modify the plateau lithosphere. Our data do not preclude a large component of post\u2013Early Eocene elevation gain (or the geodynamic mechanisms it may imply), but they do point toward Laramide-age buoyancy sources as the initial cause of significant surface uplift, ending more than 500 m.y. of residence near sea level.", "date": "2008-05", "date_type": "published", "publication": "Geological Society of America Bulletin", "volume": "120", "number": "5-6", "publisher": "Geological Society of America", "pagerange": "571-587", "id_number": "CaltechAUTHORS:20101112-143409190", "issn": "0016-7606", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101112-143409190", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0610115" }, { "agency": "NSF", "grant_number": "EAR-0408526" }, { "agency": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/B26231.1", "resource_type": "article", "pub_year": "2008", "author_list": "Flowers, R. M.; Wernicke, B. P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/0rtmr-4v424", "eprint_id": 13443, "eprint_status": "archive", "datestamp": "2023-08-22 10:59:30", "lastmod": "2023-10-17 23:54:01", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Amidon-W-H", "name": { "family": "Amidon", "given": "William H." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Burbank-W", "name": { "family": "Burbank", "given": "Douglas W." } }, { "id": "Pratt-Sitaula-B", "name": { "family": "Pratt-Sitaula", "given": "Beth" } } ] }, "title": "Anomalous cosmogenic ^3He production and elevation scaling in the high Himalaya", "ispublished": "pub", "full_text_status": "restricted", "keywords": "He-3; Li-6; lithium; helium; apatite; zircon; kyanite; garnet; Nepal; Himalayas; paleoelevation", "note": "\u00a9 2008 Received 12 July 2007; received in revised form 10 October 2007; accepted 11 October 2007. Available online 22 October 2007.We thank Don Burnett for numerous helpful discussions. We also acknowledge funding from NSF award #\n0511053.\n\nCorrection to \"Cosmogenic and nucleogenic ^3He in apatite, titanite, and zircon\" and \"Anomalous cosmogenic ^3He production and elevation scaling in the high Himalaya\" [Earth Planet. Sci. Lett. 248 (2006) 451\u2013461 and 265 (2008) 287\u2013301].\nhttp://resolver.caltech.edu/CaltechAUTHORS:20090727-150215694", "abstract": "The production rate of cosmogenic ^3He in apatite, zircon, kyanite and garnet was obtained by cross-calibration against ^(10)Be in co-existing quartz in glacial moraine boulders from the Nepalese Himalaya. The boulders have ^(10)Be ages between 6 and 16 kyr and span elevations from 3200 to 4800 m. In all of these minerals ^3He correlates with ^(10)Be and is dominantly cosmogenic in origin. After modest correction for non-cosmogenic components, ^3He/^(10)Be systematics imply apparent sea-level high-latitude (SLHL) apparent production rates for ^3He of 226 atoms g^(-1) yr^(-1) in zircon, 254 atoms g^(-1) yr^(-1) in apatite, 177 atoms g^(-1) yr^(-1) in kyanite, and 153 atoms g^(-1) yr^(-1) in gamet. These production rates are unexpectedly high compared with rates measured elsewhere in the world, and also compared with proposed element-specific production rates. For apatite and zircon, the data are sufficient to conclude that the ^3He/^(10)Be ratio increases with elevation. If this reflects different altitudinal scaling between production rates for the two isotopes then the SLHL production rates estimated by our approach are overestimates. We consider several hypotheses to explain these observations, including production of ^3He via thermal neutron capture on ^6Li, altitudinal variations in the energy spectrum of cosmic-ray neutrons, and the effects of snow cover. Because all of these effects are small, we conclude that the altitudinal variations in production rates of cosmogenic ^3He and ^(10)Be are distinct from each other at least at this location over the last last ~10 kyr kyr. This conclusion calls into question commonly adopted geographic scaling laws for at least some cosmogenic nuclides. If confirmed, this distinction may provide a mechanism by which to obtain paleoelevation estimates.", "date": "2008-01-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "265", "number": "1-2", "publisher": "Elsevier", "pagerange": "287-301", "id_number": "CaltechAUTHORS:AMIepsl08", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:AMIepsl08", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "0511053" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2007.10.022", "resource_type": "article", "pub_year": "2008", "author_list": "Amidon, William H.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/cgvmb-91080", "eprint_id": 37493, "eprint_status": "archive", "datestamp": "2023-08-22 10:37:37", "lastmod": "2023-10-23 17:41:15", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clark-M-K", "name": { "family": "Clark", "given": "Marin K." }, "orcid": "0000-0002-6141-8422" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Sierra Nevada river incision from\n apatite ^4He/^3He thermochronometry", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2007 American Geophysical Union.\n\nPublished - Farley_2007pF2186.pdf
", "abstract": "Published erosion rates suggest that acceleration of\nriver incision beginning some time before 3 Ma initiated\nformation of the deep river canyons in the southern\nSierra Nevada. Such acceleration signals a change\nin erosional efficacy but its initial timing is poorly constrained.\nIncreased erosional efficacy caused by elevation\ngain is predicted by scenarios such as block faulting,\nmantle lithosphere removal, and passage of a slab\nwindow. The timing and magnitude of elevation gain\nmay be used to distinguish between competing mechanisms.\nAs in many landscapes, the small magnitude ( <\n1.5 km) and antiquity of river incision in the Sierra\nNevada make the timing of landscape evolution and\nits relation to tectonic scenarios inaccessible by most\nmethods. Until recently, we have lacked the potential\nto 'see' erosional events that exhume leas than several\nkilometers and that occur over several to several tens\nof millions of years.", "date": "2007-12", "date_type": "published", "publication": "Eos", "volume": "88", "number": "52", "publisher": "American Geophysical Union", "pagerange": "F2186-F2186", "id_number": "CaltechAUTHORS:20130313-103852445", "issn": "0096-3941", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130313-103852445", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Farley_2007pF2186.pdf", "url": "https://authors.library.caltech.edu/records/cgvmb-91080/files/Farley_2007pF2186.pdf" }, "resource_type": "article", "pub_year": "2007", "author_list": "Clark, Marin K. and Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/hf3gm-hn937", "eprint_id": 20795, "eprint_status": "archive", "datestamp": "2023-08-22 10:31:08", "lastmod": "2023-10-20 23:27:40", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Simoes-M", "name": { "family": "Simoes", "given": "Martine" } }, { "id": "Avouac-J-P", "name": { "family": "Avouac", "given": "Jean-Philippe" }, "orcid": "0000-0002-3060-8442" }, { "id": "Beyssac-O", "name": { "family": "Beyssac", "given": "Olivier" } }, { "id": "Goff\u00e9-B", "name": { "family": "Goff\u00e9", "given": "Bruno" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Chen-Yue-Gau", "name": { "family": "Chen", "given": "Yue-Gau" }, "orcid": "0000-0002-8693-583X" } ] }, "title": "Mountain building in Taiwan: A thermokinematic model", "ispublished": "pub", "full_text_status": "public", "keywords": "mountain building; kinematics; exhumation; thermal structure; Taiwan", "note": "\u00a9 2007 American Geophysical Union.\nReceived 30 October 2006; revised 18 June 2007; accepted 6 July 2007; published 28 November 2007.\nM.S. wishes to thank Pierre Henry and\nLaurent Bollinger for introducing her to the FEAP program used in\nmodeling the evolution of the Taiwan mountain belt. Heat flow data were\nkindly provided by Kuo-Fong Ma and T.-R. A. Song. We are also grateful\nto Horng-Yuan Yen for providing Bouguer anomaly data corrected for the\nsurface density of 2.76 and to Yi-Min Wu for providing relocalized\nseismicity data. This manuscript improved thanks to the comments by\nSteven Kidder and the thoughtful discussions with John Suppe. It also\nbenefited from the constructive reviews of Tim Byrne, Don Fisher, and\nJacques Malavieille, as well as from the comments of the AE Gregory\nMoore. This study has been partly funded by the Gordon and Betty Moore\nFoundation. This is Caltech Tectonics Observatory contribution 73.\n\nPublished - simoesJGR2007b.pdf
", "abstract": "The Taiwan mountain belt is classically viewed as a case example of a critical wedge growing essentially by frontal accretion and therefore submitted to distributed shortening. However, a number of observations call for a significant contribution of underplating to the growth of the orogenic wedge. We propose here a new thermokinematic model of the Taiwan mountain belt reconciling existing kinematic, thermometric and thermochronological constraints. In this model, shortening across the orogen is absorbed by slip on the most frontal faults of the foothills. Crustal thickening and exhumation are sustained by underplating beneath the easternmost portion of the wedge (Tananao Complex, TC), where the uplift rate is estimated to ~6.3 mm a^(\u22121), and beneath the westernmost internal region of the orogen (Hsueshan Range units, HR), where the uplift rate is estimated to ~4.2 mm a^(\u22121). Our model suggests that the TC units experienced a synchronous evolution along strike despite the southward propagation of the collision. It also indicates that they have reached a steady state in terms of cooling ages but not in terms of peak metamorphic temperatures. Exhumation of the HR units increases northward but has not yet reached an exhumational steady state. Presently, frontal accretion accounts for less than ~10% of the incoming flux of material into the orogen, although there is indication that it was contributing substantially more (~80%) before 4 Ma. The incoming flux of material accreted beneath the TC significantly increased 1.5 Ma ago. Our results also suggest that the flux of material accreted to the orogen corresponds to the top ~7 km of the upper crust of the underthrust Chinese margin. This indicates that a significant amount (~76%) of the underthrust material has been subducted into the mantle, probably because of the increase in density associated with metamorphism. We also show that the density distribution resulting from metamorphism within the orogenic wedge explains well the topography and the gravity field. By combining available geological data on the thermal and kinematic evolution of the wedge, our study sheds new light onto mountain building processes in Taiwan and allows for reappraising the initial structural architecture of the passive margin.", "date": "2007-11-28", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "112", "number": "B11", "publisher": "American Geophysical Union", "pagerange": "Art. No. B11405", "id_number": "CaltechAUTHORS:20101115-093735810", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101115-093735810", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "73", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Caltech-Tectonics-Observatory.-Taiwan-Tectonics-and-Seismicity" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2006JB004824", "primary_object": { "basename": "simoesJGR2007b.pdf", "url": "https://authors.library.caltech.edu/records/hf3gm-hn937/files/simoesJGR2007b.pdf" }, "resource_type": "article", "pub_year": "2007", "author_list": "Simoes, Martine; Avouac, Jean-Philippe; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ynfy2-y8q51", "eprint_id": 20797, "eprint_status": "archive", "datestamp": "2023-08-22 10:24:26", "lastmod": "2023-10-20 23:27:47", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Beyssac-O", "name": { "family": "Beyssac", "given": "Olivier" } }, { "id": "Simoes-M", "name": { "family": "Simoes", "given": "Martine" } }, { "id": "Avouac-J-P", "name": { "family": "Avouac", "given": "Jean-Philippe" }, "orcid": "0000-0002-3060-8442" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Chen-Yue-Gau", "name": { "family": "Chen", "given": "Yue-Gau" }, "orcid": "0000-0002-8693-583X" }, { "id": "Chan-Yu-Chang", "name": { "family": "Chan", "given": "Yu-Chang" } }, { "id": "Goff\u00e9-B", "name": { "family": "Goff\u00e9", "given": "Bruno" } } ] }, "title": "Late Cenozoic metamorphic evolution and exhumation of Taiwan", "ispublished": "pub", "full_text_status": "public", "keywords": "Taiwan; exhumation; metamorphism", "note": "\u00a9 2007 American Geophysical Union.\n\nReceived 25 October 2006; revised 5 April 2007; accepted 26 June 2007; published 7 November 2007.\nWe are indebted to Georges Rossman and\nLiz Miura-Boyd for access to the Raman laboratory at Caltech (California,\nUSA) as well as for many instructive discussions. In the field we\nappreciated the help of Sylvain Bernard (ENS, France), Frank Yang,\nChin-Ying Lan, Yu-ting Kuo, and Chung Huang as well as of many other\nstudents from NTU (Taiwan). The numerous thin sections were prepared by\nRoland Caron (ENS, France). The ZHe data were analyzed by Lindsey\nHedges (Caltech). This study was improved thanks to the numerous\ndiscussions with Kerry Sieh, Bruce Shyu, and Mark Simons (Caltech), as\nwell as with John Suppe (Princeton) and Jacques Malavieille (CNRS\nMontpellier). Mark Simons also collected the Chipan gneiss samples. Steve\nKidder (Caltech) provided constructive comments on an early draft. This\nmanuscript also benefited from the constructive and thoughtful reviews of\nTim Byrne and Sean Willett, and from the comments of the Associate\nEditor K. Stuewe. This project was funded by the IT program (INSUCNRS,\nFrance) and by the Gordon and Betty Moore Foundation. This is\nCaltech Tectonics Observatory contribution 70.\n\nPublished - BeyssacTectonics2007.pdf
", "abstract": "The Taiwan mountain belt is composed of a Cenozoic slate belt (Hsuehshan Range units, HR, and Backbone Slates, BS) and of accreted polymetamorphic basement rocks (Tananao Complex, TC). Ongoing crustal shortening has resulted from the collision between the Chinese continental margin and the Luzon volcanic arc, which initiated ~6.5 Ma ago. The grade and age of metamorphism and exhumation are a key record of the development of the orogenic wedge. Because the Taiwan mountain belt is mostly composed by accreted sediments lacking metamorphic index minerals, quantitative constraints on metamorphism are sparse. By contrast, these rocks are rich in carbonaceaous material (CM) and are therefore particularly appropriate for RSCM (Raman Spectroscopy of CM) thermometry. We apply this technique in addition to (U-Th)/He thermochronology on detrital zircons to assess peak metamorphic temperatures (T) and the late exhumational history respectively, along different transects in central and southern Taiwan. In the case of the HR units, we find evidence for high metamorphic T of at least 340\u00b0\u2013350\u00b0C and locally up to 475\u00b0C, and for relative rapid exhumation with zircon (U-Th)/He ages in the range of 1.5\u20132 Ma. Farther east, the BS were only slightly metamorphosed (T < 330 \u00b0C), and zircons are not reset for (U-Th)/He. From the eastern BS to the inner TC schists, T gradually increases from ~350\u00b0C up to ~500\u00b0C following an inverted metamorphic gradient. Available geochronological constraints and the continuous thermal gradient from the BS to the basement rocks of the TC suggest that the high RSCM T of the TC were most probably acquired during the last orogeny, and were not inherited from a previous thermal event. Zircons yield (U-Th)/He ages of ~0.5\u20131.2 Ma. Peak metamorphic T and the timing of exhumation do not show along-strike variations over the TC in the studied area. In contrast, exhumation is laterally diachronous and decreases southward in the case of the HR units. In particular, our data imply that the HR units have been exhumed by a minimum of 15 km over the last few Ma. In the case of the BS, they show far less cumulated exhumation and much slower cooling rates. We propose that most of the deformation and exhumation of the Taiwan mountain belt is sustained through two underplating windows located beneath the Hsuehshan Range and the TC. Our data show significant departures from the predictions of the prevailing model in Taiwan, which assumes a homogeneous critical wedge with dominant frontal accretion. Our study sheds new light on how the mountain belt has grown as a possible result of underplating mostly.", "date": "2007-11-07", "date_type": "published", "publication": "Tectonics", "volume": "26", "number": "6", "publisher": "American Geophysical Union", "pagerange": "Art. No. TC6001", "id_number": "CaltechAUTHORS:20101115-095303150", "issn": "0278-7407", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101115-095303150", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Institut National des Sciences de l'Univers/Centre National de la Recherche Scientifique (INSU/CNRS) (France)" }, { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "70", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Caltech-Tectonics-Observatory.-Taiwan-Tectonics-and-Seismicity" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2006TC002064", "primary_object": { "basename": "BeyssacTectonics2007.pdf", "url": "https://authors.library.caltech.edu/records/ynfy2-y8q51/files/BeyssacTectonics2007.pdf" }, "resource_type": "article", "pub_year": "2007", "author_list": "Beyssac, Olivier; Simoes, Martine; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/y515m-03k80", "eprint_id": 47352, "eprint_status": "archive", "datestamp": "2023-08-22 09:39:56", "lastmod": "2023-10-26 20:31:12", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flowers-R-M", "name": { "family": "Flowers", "given": "R. M." } }, { "id": "Wernicke-B-P", "name": { "family": "Wernicke", "given": "B. P." }, "orcid": "0000-0002-7659-8358" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "(U-Th)/He apatite constraints on the erosional history of the southwestern Colorado Plateau and implications for Early Tertiary uplift and carving of a \"Proto-Grand Canyon\"", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2007 Published by Elsevier Ltd.", "abstract": "Resolving the timing and relationships between regional\nunroofing, canyon incision, and topographic uplift in\ncontinental plateaus is a challenging problem. The regional\nunroofing history of the Colorado Plateau, and its relationship\nto Grand Canyon incision (up to 1.5 km) and plateau uplift\n(~1.9 km) since the Late Cretaceous, is controversial. We\nused (U-Th)/He apatite thermochronometry (36 samples, 230\nsingle-grain analyses) across the southwestern quadrant of the\nColorado Plateau to address these issues. Our data document\noverall southwest to northeast unroofing from plateau margin\nto plateau interior, during denudation phases in the Late\nCretaceous/Early Tertiary (80 to 55 Ma), mid Tertiary (28 to\n16 Ma), and Late Tertiary (<6 Ma). Distributions of apatite\ndates modeled using the radiation damage trapping model\n[1,2] suggest that eastern Grand Canyon samples from the\nbasement and the Kaibab surface nearby had similar Early to\nmid-Tertiary thermal histories, despite their ~1500 m of\nstratigraphic separation. If these models are correct, they\nindicate that a significant (\u2265 1000 m deep) paleo-Grand\nCanyon was carved in post-Paleozoic sediments in this region\nduring Early Tertiary time. Evidence for kilometer-scale\ntopographic relief would require substantial uplift during\nSevier/Laramide time, preceding regional unroofing of this\nportion of the plateau interior. Although the data do not\npreclude additional post-Laramide uplift, the subsequent\nregional unroofing phases could be explained by drainage\nreorganization associated with rift-related lowering of adjacent\nregions without additional elevation gain of the plateau.", "date": "2007-08", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "71", "number": "15", "publisher": "Elsevier", "pagerange": "A287", "id_number": "CaltechAUTHORS:20140718-155445054", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140718-155445054", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2007.06.015", "resource_type": "article", "pub_year": "2007", "author_list": "Flowers, R. M.; Wernicke, B. P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/z0wdq-1j892", "eprint_id": 20810, "eprint_status": "archive", "datestamp": "2023-08-19 20:06:52", "lastmod": "2023-10-20 23:28:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flowers-R-M", "name": { "family": "Flowers", "given": "R. M." } }, { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "D. L." } }, { "id": "Wernicke-B-P", "name": { "family": "Wernicke", "given": "B. P." }, "orcid": "0000-0002-7659-8358" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Radiation damage control on apatite (U-Th)/He dates from the Grand Canyon region, Colorado Plateau", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2007 Geological Society of America. \n\nManuscript received 22 October 2006. Revised manuscript received 21 December 2006. Manuscript accepted 29 December 2006. \n\nThis work was supported by The Caltech Tectonics Observatory and National Science Foundation grants EAR-0610115 and EAR-0408526. Constructive reviews by Trevor Dumitru, Shari Kelley, Jon Spencer, and Daniel Stockli helped to clarify the manuscript.", "abstract": "Individual detrital apatite grains from the Esplanade, Coconino, and Moenkopi Formations in the Grand Canyon region of the Colorado Plateau yield (U-Th)/He dates from 104 to 5 Ma. The range of dates within each unit far exceeds analytical uncertainty, but correlates with both He concentration [He] and effective U concentration [eU]. These dates are all significantly younger than the sandstone units, indicating partial to complete He loss following deposition. Recently published laboratory diffusion data suggest that He retentivity in apatite increases with radiation damage. Forward models predict that the consequences of this effect will be manifested most clearly as a correlation between (U-Th)/He dates and the [He] and [eU] in suites of apatites that (1) are characterized by a large span of [eU], and (2) had thermal histories in which sufficient time elapsed for the apatite He diffusion kinetics to diverge prior to reheating and partial resetting. Apatites in the sedimentary units investigated fit these cri teria. Using geologically reasonable deposition, burial, and unroofing histories, simulations that include the effect of radiation damage on apatite He retentivity can reproduce the observed distributions of apatite dates and correlations with parent and daughter concentrations. These results suggest that a span of (U-Th)/He dates positively correlated with [eU] may provide important information regarding a sample's thermal history.", "date": "2007-05", "date_type": "published", "publication": "Geology", "volume": "35", "number": "5", "publisher": "Geological Society of America", "pagerange": "447-450", "id_number": "CaltechAUTHORS:20101115-112300013", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101115-112300013", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Tectonics Observatory" }, { "agency": "NSF", "grant_number": "EAR-0610115" }, { "agency": "NSF", "grant_number": "EAR-0408526" } ] }, "other_numbering_system": { "items": [ { "id": "64", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/G23471A.1", "resource_type": "article", "pub_year": "2007", "author_list": "Flowers, R. M.; Shuster, D. L.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/taw5k-z2h73", "eprint_id": 33774, "eprint_status": "archive", "datestamp": "2023-08-22 08:08:21", "lastmod": "2023-10-18 20:39:40", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Baxter-E-F", "name": { "family": "Baxter", "given": "Ethan F." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Asimow-P-D", "name": { "family": "Asimow", "given": "Paul D." }, "orcid": "0000-0001-6025-8925" } ] }, "title": "Grain boundary partitioning of Ar and He", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2006 Elsevier Inc.\nReceived 5 July 2005; accepted in revised form 12 September 2006.\nThis study was conducted at Caltech. Manuscript preparation\nwas conducted while EFB was at Boston University.\nWe Jed Mosenfelder, John Beckett and Mike Baker for help with the experiments. We thank Pete Burnard for\nassistance with the noble gas analysis. We thank Carol\nGarland for TEM preparation and analysis. Steve Reese\nof the OSU Reactor Facility was helpful in accommodating\nour irradiations. We thank Lauren Cooper and Jennifer\nWade for assistance in thin section observation. Ed Stolper\nprovided the starting material and access to his labs. We\nthank Bruce Watson, Takeo Hiraga, and Terry Plank for\nvaluable discussions at various stages of the project. Support from a Caltech Postdoctoral Fellowship to EFB and\nNSF Grants EAR-0125784 (to PDA and KAF) and EAR-0337527 (to EFB) is gratefully acknowledged.\nAssociate Editor: Jun-ichi Matsuda\nSupplementary data associated with this article can be\nfound, in the online version, at doi:10.1016/j.gca.2006.09.011.\n\nSupplemental Material - mmc1.doc
Supplemental Material - mmc2.doc
Supplemental Material - mmc3.pdf
Supplemental Material - mmc4.pdf
", "abstract": "An experimental procedure has been developed that permits measurement of the partitioning of Ar and He between crystal interiors and the intergranular medium (ITM) that surrounds them in synthetic melt-free polycrystalline diopside aggregates. ^(37)Ar and ^(4)He are introduced into the samples via neutron irradiation. As samples are crystallized under sub-solidus conditions from a pure diopside glass in a piston cylinder apparatus, noble gases diffusively equilibrate between the evolving crystal and intergranular reservoirs. After equilibration, ITM Ar and He is distinguished from that incorporated within the crystals by means of step heating analysis. An apparent equilibrium state (i.e., constant partitioning) is reached after about 20 h in the 1450 \u00b0C experiments. Data for longer durations show a systematic trend of decreasing ITM Ar (and He) with decreasing grain boundary (GB) interfacial area as would be predicted for partitioning\ncontrolled by the network of planar grain boundaries (as opposed to ITM gases distributed in discrete micro-bubbles or melt).\nThese data yield values of GB-area-normalized partitioning, K\u00af^(Ar)_(ITM), with units of (Ar/m^3 of solid)/(Ar/m^2 of GB) of 6.8 x 10^3 \u2013 2.4 x 104 m^(-1). Combined petrographic microscope, SEM, and limited TEM observation showed no evidence that a residual glass phase or grain boundary micro-bubbles dominated the ITM, though they may represent minor components. If a nominal GB thickness (\u03b4) is assumed, and if the density of crystals and the grain boundaries are assumed equal, then a true grain boundary partition coefficient (K^(Ar)_(GB) = X^(Ar)_(crystals)/X^(Ar)_(GB) may be determined. For reasonable values of \u03b4, K^(Ar)_(GB) is at least an order of magnitude lower than the Ar partition coefficient between diopside and melt. Helium partitioning data provide a less robust constraint with K\u00af^(He)_(ITM) between 4 x 10^3 and 4 x 10^4 cm^(-1), similar to the Ar partitioning data. These data suggest that an ITM consisting of nominally melt free, bubble free, tight grain boundaries can constitute a significant but not infinite reservoir, and therefore bulk transport pathway, for noble gases in fine grained portions of the crust and mantle where aqueous or melt fluids are non-wetting and of very low abundance (i.e., <0.1% fluid). Heterogeneities in grain size within dry equilibrated systems will correspond to significant differences in bulk rock noble gas content.", "date": "2007-01-15", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "71", "number": "2", "publisher": "Elsevier", "pagerange": "434-451", "id_number": "CaltechAUTHORS:20120831-112949050", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120831-112949050", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech" }, { "agency": "NSF", "grant_number": "EAR-0125784" }, { "agency": "NSF", "grant_number": "EAR-0337527" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2006.09.011", "primary_object": { "basename": "mmc3.pdf", "url": "https://authors.library.caltech.edu/records/taw5k-z2h73/files/mmc3.pdf" }, "related_objects": [ { "basename": "mmc4.pdf", "url": "https://authors.library.caltech.edu/records/taw5k-z2h73/files/mmc4.pdf" }, { "basename": "mmc1.doc", "url": "https://authors.library.caltech.edu/records/taw5k-z2h73/files/mmc1.doc" }, { "basename": "mmc2.doc", "url": "https://authors.library.caltech.edu/records/taw5k-z2h73/files/mmc2.doc" } ], "resource_type": "article", "pub_year": "2007", "author_list": "Baxter, Ethan F.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/rpv63-35g48", "eprint_id": 20822, "eprint_status": "archive", "datestamp": "2023-08-19 19:15:35", "lastmod": "2024-01-13 00:06:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Saleeby-J-B", "name": { "family": "Saleeby", "given": "J." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Kistler-R-W", "name": { "family": "Kistler", "given": "R. W." } }, { "id": "Fleck-R", "name": { "family": "Fleck", "given": "R." } } ] }, "title": "Thermal evolution and exhumation of deep-level batholithic exposures, southernmost Sierra Nevada, California", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Sierra Nevada, thermochronology, rapid exhumation", "note": "\u00a9 2007 Geological Society of America. \nManuscript accepted by the Society 13 July 2006.\nThis research was funded by National Science Foundation\ngrants EAR-9526859 and EAR-0087347 (to J.S.), and EAR-\n0230383 (to J.S. and K.F.), and the Gordon and Betty Moore Foundation.\nThis is Caltech Tectonic Observatory Contribution number\n49. This research benefited from discussions and field excursions\nwith M. Ducea, L.T. Silver, R.K. O'Nions, P.D. Asimow, D.A.\nPickett, D.J. Wood, P.J. Wyllie, and J. Eiler. Field, laboratory, and computational assistance by L. Hedges, E. Nadin, and Z. Foster-\nSaleeby and assistance in manuscript preparation by Kim Klotz are\nkindly acknowledged. Limited access to private lands held by the\nTejon Ranch Company is gratefully acknowledged.", "abstract": "The Tehachapi complex lies at the southern end of the Sierra Nevada batholith adjacent to the Neogene-Quaternary Garlock fault. The complex is composed principally of high-pressure (8\u201310 kbar) Cretaceous batholithic rocks, and it represents the deepest exposed levels of a continuous oblique crustal section through the southern Sierra Nevada batholith. Over the southern ~100 km of this section, structural/petrologic continuity and geochronological data indicate that \u226535 km of felsic to intermediate-composition crust was generated by copious arc magmatism primarily between 105 and 99 Ma. In the Tehachapi complex, these batholithic rocks intrude and are bounded to the west by similar-composition gneissic-textured high-pressure batholithic rocks emplaced at ca. 115\u2013110 Ma. This lower crustal complex is bounded below by a regional thrust system, which in Late Cretaceous time tectonically eroded the underlying mantle lithosphere, and in series displaced and underplated the Rand Schist subduction assemblage by low-angle slip from the outboard Franciscan trench. Geophysical and mantle xenolith studies indicate that the remnants of this shallow subduction thrust descend northward through the crust and into the mantle, leaving the mantle lithosphere intact beneath the greater Sierra Nevada batholith. This north-dipping regional structure records an inflection in the Farallon plate, which was segmented into a shallow subduction trajectory to the south and a normal steeper trajectory to the north.\n\nWe combine new and published data from a broad spectrum of thermochronometers that together form a coherent data array constraining the thermal evolution of the complex. Integration of these data with published thermobarometric and petrogenetic data also constrains the tectonically driven decompression and exhumation history of the complex. The timing of arc magmatic construction of the complex, as denoted above, is resolved by a large body of U/Pb zircon ages. High-confidence thermochronometric data track a single retrogressing path commencing from widely established solidus conditions at ca. 100 Ma, and traversing through time-temperature space as follows: (1) Sm/Nd garnet ~770\u2013680 \u00b0C at ca. 102\u201395 Ma, (2) U/Pb titanite ~750\u2013600 \u00b0C at ca. 102\u201395 Ma, (3) Ar/Ar hornblende ~570\u2013490 \u00b0C at ca. 94\u201391 Ma, (4) Rb/Sr biotite ~390\u2013260 \u00b0C at ca. 90\u201386 Ma, (5) Ar/Ar biotite ~320\u2013240 \u00b0C at ca. 88\u201385 Ma, and (6) (U-Th)/He zircon ~230\u2013170 \u00b0C at ca. 88\u201383 Ma. Additional stratigraphic constraints place the complex at surface conditions in Paleocene\u2013early Eocene time (ca. 66\u201355 Ma).\n\nIntegration of these results with thermobarometric and structural data, including published data on the underlying Rand Schist, reveals a profound tectonic event whereby rapid cooling and exhumation at rates potentially as high as 100s \u00b0C/m.y. and >5 mm/yr initiated at ca. 98 Ma and peaked between 96 and 94 Ma. Between 93 and 85 Ma, cooling rates remained high, but decelerated with or without significant exhumation. Subsequent cooling and exhumation rates are poorly constrained but were much slower and ultimately resulted in Paleocene-Eocene surface exposure. Initial rapid exhumation and cooling are hypothesized to have been driven by abrupt flattening in the corresponding segment of the Farallon plate and the resulting tectonic erosion of the underlying mantle lithosphere. Protolith as well as metamorphic pressure-temperature and age constraints on the Rand Schist indicate its rapid low-angle subduction between 93 and 88 Ma. Comparison of the Rand Schist and Tehachapi complex pressure-temperature-time paths in conjunction with structural relations strongly suggest that the schist ascended the equivalent of ~4 kbar relative to the Tehachapi complex by low-angle normal displacement along the Rand fault between 88 and 80 Ma to attain its current underplated structural position. Such extensional tectonism is hypothesized to have been driven by slab rollback during the demise of the southern California region shallow slab segment.", "date": "2007", "date_type": "published", "publisher": "Geological Society of America", "place_of_pub": "Boulder, CO", "pagerange": "39-66", "id_number": "CaltechAUTHORS:20101116-085627262", "isbn": "978-0-8137-2419-5", "book_title": "Convergent margin terranes and associated regions : a tribute to W.G. Ernst", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101116-085627262", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9526859" }, { "agency": "NSF", "grant_number": "EAR-0087347" }, { "agency": "NSF", "grant_number": "EAR-0230383" }, { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "49", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Cloos-M", "name": { "family": "Cloos", "given": "M." } }, { "id": "Carlson-W-D", "name": { "family": "Carlson", "given": "W. D." } }, { "id": "Gilbert-M-C", "name": { "family": "Gilbert", "given": "M. C." } }, { "id": "Liou-J-G", "name": { "family": "Liou", "given": "J. G." } }, { "id": "Sorensen-S-S", "name": { "family": "Sorensen", "given": "S. S." } } ] }, "doi": "10.1130/2007.2419(02)", "resource_type": "book_section", "pub_year": "2007", "author_list": "Saleeby, J.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/kc02v-b9156", "eprint_id": 15528, "eprint_status": "archive", "datestamp": "2023-08-22 06:20:56", "lastmod": "2023-10-19 14:32:24", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Libarkin-J", "name": { "family": "Libarkin", "given": "J." } }, { "id": "Mukhopadhyay-S", "name": { "family": "Mukhopadhyay", "given": "S." } }, { "id": "Amidon-W-H", "name": { "family": "Amidon", "given": "W." } } ] }, "title": "Cosmogenic and nucleogenic ^3He in apatite, titanite, and zircon", "ispublished": "pub", "full_text_status": "public", "keywords": "cosmogenic helium; apatite; zircon; titanite; production rate; Altiplano", "note": "\u00a9 2006 Elsevier. \n\nReceived 7 April 2006; revised 6 June 2006; accepted 6 June 2006. Editor: R.W. Carlson. Available online 17 July 2006. \n\nWe thank C. Garzione for field assistance and thoughtful discussion and Don Burnett for numerous helpful conversations regarding nuclear processes. We also acknowledge two anonymous reviewers. This research was supported by the National Science Foundation EAR (0350396, Libarkin); EAR (0408526, Farley); and by funds provided to SM by Harvard University.\n\nCorrection to \"Cosmogenic and nucleogenic ^3He in apatite, titanite, and zircon\" and \"Anomalous cosmogenic ^3He production and elevation scaling in the high Himalaya\" [Earth Planet. Sci. Lett. 248 (2006) 451\u2013461 and 265 (2008) 287\u2013301].\nhttp://resolver.caltech.edu/CaltechAUTHORS:20090727-150215694\n\nSupplemental Material - Table_S1.doc
Supplemental Material - Table_S2.doc
", "abstract": "Cosmogenic ^3He was measured in apatite, titanite, and zircon and cosmogenic ^(21)Ne in quartz at 13 depth intervals in a 2.7-m long drill core in a Miocene ignimbrite from the Altiplano of Bolivia. All three ^3He depth profiles as well as the ^(21)Ne profile attenuate exponentially with depth, indicating that both of these isotopes are cosmogenic in origin with no significant contribution from other sources. The attenuation lengthscale for ^3He production of \u039b = 180 \u00b1 11 g/cm^2 is consistent with expectations for neutron spallation, and is identical to that found for the cosmogenic ^(21)Ne in quartz. By normalizing the measured ^3He concentrations to ^(21)Ne and using the independently known cosmogenic ^(21)Ne production rate, the apparent cosmogenic ^3He production rates in apatite, titanite, and zircon were respectively found to be 112, 97, and 87 atoms/g/yr at sea-level and high latitude. The formal uncertainty on these estimates is ~20% (2\u03c3), and arises in equal parts from uncertainties in the measured ^3He/^(21)Ne ratios and the uncertainty in the ^(21)Ne production rate. However an additional factor affecting the apparent ^3He production rate in these phases arises from the long stopping range of spalled ^3He and tritium (which decays to ^3He). Because all three accessory phases have higher mean atomic number than major rock-forming minerals, they will have lower 3He production rates than their surroundings. As a consequence the long stopping ranges will cause a net implantation of ^3He and therefore higher apparent production rates than would apply for purely in-situ production. Thus these apparent production rates apply only to the specific grain sizes analyzed. Analysis of sieved zircon aliquots suggests that a factor of 2 increase in grain size (from ~50 to ~100 \u03bcm cross-section) yields a 10% decrease in apparent production rate. While this effect warrants further study, the grain sizes analyzed here are typical of the accessory phases commonly encountered, so the apparent rates provide an appropriate starting place for surface exposure dating using ^3He in these minerals.", "date": "2006-08-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "248", "number": "1-2", "publisher": "Elsevier", "pagerange": "451-461", "id_number": "CaltechAUTHORS:20090901-133907935", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090901-133907935", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR 0350396" }, { "agency": "NSF", "grant_number": "EAR 0408526" }, { "agency": "Harvard University" } ] }, "other_numbering_system": { "items": [ { "id": "46", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2006.06.008", "primary_object": { "basename": "Table_S1.doc", "url": "https://authors.library.caltech.edu/records/kc02v-b9156/files/Table_S1.doc" }, "related_objects": [ { "basename": "Table_S2.doc", "url": "https://authors.library.caltech.edu/records/kc02v-b9156/files/Table_S2.doc" } ], "resource_type": "article", "pub_year": "2006", "author_list": "Farley, K. A.; Libarkin, J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/y08ft-0tx75", "eprint_id": 47354, "eprint_status": "archive", "datestamp": "2023-08-22 06:14:03", "lastmod": "2023-10-26 20:31:17", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flowers-R-M", "name": { "family": "Flowers", "given": "R. M." } }, { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "D. L." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Wernicke-B-P", "name": { "family": "Wernicke", "given": "B. P." }, "orcid": "0000-0002-7659-8358" } ] }, "title": "Evidence for radiation damage control on apatite He ages from the Grand Canyon region, Colorado Plateau", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2006 Published by Elsevier Ltd.", "abstract": "Individual detrital apatites from three sedimentary units in\nthe Grand Canyon region of the Colorado Plateau yield a span\nof (U-Th)/He dates that are positively correlated with\nradiogenic ^4He and effective U (eU) concentrations. All dates\nare younger than the depositional ages of the sandstone units,\nindicating partial to complete ^4He loss in the analyzed apatites\nfollowing deposition. Recent refinements in our\nunderstanding of He diffusion based on laboratory\nexperiments suggest that radiation damage impedes He\nmobility in apatite [1]. Forward models that incorporate the\neffect of evolving He diffusivities indicate that this behavior\nwill be most strongly manifested by suites of apatites\ncontaining a range of eU concentrations that cooled and were\npartially reset. Detrital apatite grains from sedimentary units\nin the Grand Canyon region fit these criteria when 1)\ncompositionally variable apatites were deposited, and 2)\nunderwent burial heating, partial ^4He loss, and subsequent\nexhumation. Using geologically reasonable thermal histories,\nour simulations can reproduce our distributions of detrital\napatite dates. The youngest dates are obtained for the lowest\neU apatites that underwent the greatest ^4He loss during burial,\nand impose the strongest constraint on the exhumation\ntiming. The results also predict that the correlations between\nage and ^4He and eU concentrations are sensitive to the\nthermal history, such that it may be possible to extract\nadditional details regarding temperature-time paths from\nthese relationships.", "date": "2006-08", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "70", "number": "18", "publisher": "Elsevier", "pagerange": "A178", "id_number": "CaltechAUTHORS:20140721-082435010", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140721-082435010", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2006.06.358", "resource_type": "article", "pub_year": "2006", "author_list": "Flowers, R. M.; Shuster, D. L.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/qye8e-q6f56", "eprint_id": 68924, "eprint_status": "archive", "datestamp": "2023-08-22 05:17:14", "lastmod": "2023-10-20 16:20:28", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clark-M-K", "name": { "family": "Clark", "given": "M. K." }, "orcid": "0000-0002-6141-8422" }, { "id": "Mah\u00e9o-G", "name": { "family": "Maheo", "given": "G." } }, { "id": "Saleeby-J-B", "name": { "family": "Saleeby", "given": "J." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "The non-equilibrium landscape of the Sierra Nevada, California: Reply", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2006 Geological Society of America. \n\nManuscript accepted 27 January 2006; published online April 2006.", "abstract": "We thank H.F. Garner for calling attention to an important\nfactor governing fluvial erosion: the role of variable stream\ndischarge caused by climatic fluctuations. We agree that climatic\nvariations affect erosion rates and stream morphology\nby altering stream discharge, altering bed state such as armoring\nof channel bottoms and changing sedimentary flux, and\ncan vary local base levels during glacial/interglacial cycles.\nThese processes have most likely played a role in changing\nriver profile form and erosion rates to some degree at various\ntimes throughout the Cenozoic in the Sierra Nevada. However,\nGarner argues that climatically driven changes in erosion rate\nled to elevation change through isostatic adjustment without\nany need to call on tectonic forces to explain the modern\nelevation of the range. This is where we disagree.", "date": "2006-03", "date_type": "published", "publication": "GSA Today", "volume": "16", "number": "3", "publisher": "Geological Society of America", "pagerange": "e11-e12", "id_number": "CaltechAUTHORS:20160708-113232721", "issn": "1052-5173", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160708-113232721", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/GSATOFe11", "resource_type": "article", "pub_year": "2006", "author_list": "Clark, M. K.; Maheo, G.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/53ypt-4tn81", "eprint_id": 36663, "eprint_status": "archive", "datestamp": "2023-08-22 04:59:53", "lastmod": "2023-10-20 23:28:02", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Vokrouhlick\u00fd-D", "name": { "family": "Vokrouhlick\u00fd", "given": "David" } }, { "id": "Bottke-W-F", "name": { "family": "Bottke", "given": "William F." } }, { "id": "Nesvorn\u00fd-D", "name": { "family": "Nesvorn\u00fd", "given": "David" } } ] }, "title": "A late Miocene dust shower from the break-up of an asteroid in the main belt", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2006 Nature Publishing Group, a division of Macmillan Publishers Limited.\n\nReceived 21 June 2005; Accepted 31 October 2005.\n\nFinancial support for this project was provided by NASA's\nPlanetary Geology & Geophysics program (W.F.B., D.N. and K.A.F.). Financial and travel support for D.V. was provided by the Czech Republic grant agency and NSF's COBASE program. We also thank D. Durda, A. Morbidelli, M. Sykes and S. Mukhopadhyay for several discussions, and S. Goldstein and J. Burns for comments and suggestions.\n\nAuthor Contributions: K.A.F. measured 3He in the seafloor sediments. D.N.\ndetermined the age of the Veritas family using numerical integration methods.\nD.V., W.F.B. and D.N. constructed the Monte Carlo dust evolution code and\nanalysed the results.\n\nSupplemental Material - nature04391-s1.pdf
", "abstract": "Throughout the history of the Solar System, Earth has been bombarded by interplanetary dust particles (IDPs), which are asteroid and comet fragments of diameter ~1\u20131,000 \u03bcm. The IDP flux is believed to be in quasi-steady state: particles created by episodic main belt collisions or cometary fragmentation replace those removed by comminution, dynamical ejection, and planetary or solar impact. Because IDPs are rich in ^(3)He, seafloor sediment ^(3)He concentrations provide a unique means of probing the major events that have affected the IDP flux and its source bodies over geological timescales. Here we report that collisional disruption of the >150-km-diameter asteroid that created the Veritas family 8.3 \u00b1 0.5 Myr ago5 also produced a transient increase in the flux of interplanetary dust-derived ^(3)He. The increase began at 8.2 \u00b1 0.1 Myr ago, reached a maximum of approx4 times pre-event levels, and dissipated over ~1.5 Myr. The terrestrial IDP accretion rate was overwhelmingly dominated by Veritas family fragments during the late Miocene. No other event of this magnitude over the past ~10^8 yr has been deduced from main belt asteroid orbits. One remarkably similar event is present in the \u00b1 record 35 Myr ago, but its origin by comet shower or asteroid collision remains uncertain.", "date": "2006-01-19", "date_type": "published", "publication": "Nature", "volume": "439", "number": "7074", "publisher": "Nature Publishing Group", "pagerange": "295-297", "id_number": "CaltechAUTHORS:20130129-140306410", "issn": "0028-0836", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130129-140306410", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" }, { "agency": "Czech Republic grant agency" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/nature04391", "primary_object": { "basename": "nature04391-s1.pdf", "url": "https://authors.library.caltech.edu/records/53ypt-4tn81/files/nature04391-s1.pdf" }, "resource_type": "article", "pub_year": "2006", "author_list": "Farley, Kenneth A.; Vokrouhlick\u00fd, David; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/z2j1k-z5e84", "eprint_id": 35581, "eprint_status": "archive", "datestamp": "2023-08-22 04:36:06", "lastmod": "2023-10-20 19:10:56", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "David L." } }, { "id": "Ehlers-T-A", "name": { "family": "Ehlers", "given": "Todd A." } }, { "id": "Rusmore-M-E", "name": { "family": "Rusmore", "given": "Margaret E." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Rapid Glacial Erosion at 1.8 Ma Revealed by ^4He/^3He Thermochronometry", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2005 American Association for the Advancement of Science. \n\nReceived for publication 8 August 2005; accepted for publication 7 November 2005. \n\nWe thank G. Woodsworth for assistance in sample collection and providing access to the Digital Elevation Model used in Fig. 1 through collaboration with the Geologic Survey of Canada. We also thank J. M. Sisterson for help with the proton irradiation, L. M. Hedges for help with sample preparation, and M. S. Densmore. This work was supported by NSF grants EAR-0408526 and 0309779.\n\nSupplemental Material - Shuster.SOM.pdf
", "abstract": "Alpine glaciation and river incision control the topography of mountain ranges, but their relative contributions have been debated for years. Apatite ^(4)He/^(3)He thermochronometry tightly constrains the timing and rate of glacial erosion within one of the largest valleys in the southern Coast Mountains of British Columbia, Canada. Five proximate samples require accelerated denudation of the Klinaklini Valley initiating 1.8 \u00b1 0.2 million years ago (Ma). At least 2 kilometers of overlying rock were removed from the valley at \u22655 millimeters per year, indicating that glacial valley deepening proceeded \u22656 times as fast as erosion rates before \u223c1.8 Ma. This intense erosion may be related to a global transition to enhanced climate instability \u223c1.9 Ma.", "date": "2005-12-09", "date_type": "published", "publication": "Science", "volume": "310", "number": "5754", "publisher": "American Association for the Advancement of Science", "pagerange": "1668-1670", "id_number": "CaltechAUTHORS:20121120-142240847", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-142240847", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0408526" }, { "agency": "NSF", "grant_number": "EAR-0309779" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.1118519", "primary_object": { "basename": "Shuster.SOM.pdf", "url": "https://authors.library.caltech.edu/records/z2j1k-z5e84/files/Shuster.SOM.pdf" }, "resource_type": "article", "pub_year": "2005", "author_list": "Shuster, David L.; Ehlers, Todd A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/gjzcq-3ha42", "eprint_id": 35541, "eprint_status": "archive", "datestamp": "2023-08-22 04:34:54", "lastmod": "2023-10-20 19:07:09", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Ward-P-D", "name": { "family": "Ward", "given": "P." } }, { "id": "Garrison-G", "name": { "family": "Garrison", "given": "G." } }, { "id": "Mukhopadhyay-S", "name": { "family": "Mukhopadhyay", "given": "S." } } ] }, "title": "Absence of extraterrestrial ^3He in Permian\u2013Triassic age sedimentary rocks", "ispublished": "pub", "full_text_status": "restricted", "keywords": "extraterrestrial helium; cosmic dust; Permian-Triassic boundary; fullerene", "note": "\u00a9 2005 Elsevier B.V. Received 29 March 2005; received in revised form 19 July 2005; accepted 22 September 2005.\nAvailable online 2 November 2005. Editor: V. Courtillot. This work was supported by a NASA Astrobiology\nInstitute grant.", "abstract": "Helium concentration and isotopic composition were measured in a suite of samples across the Permian\u2013Triassic boundary at Opal Creek, Canada, to determine whether high extraterrestrial helium concentrations are associated with a possible extinction-inducing impact event at this time. No extraterrestrial ^3He was detected, implying that neither fullerene-hosted nor IDP-hosted He is present at or near the boundary. This observation is consistent with similar studies of some Permian\u2013Triassic sections, but contrasts sharply with reports of both fullerene- and IDP-hosted extraterrestrial ^3He at other sections.\nStep-heat experiments indicate rapid diffusion of extraterrestrial helium from sediments heated to temperatures above \u223c 70 \u00b0C. Given the likelihood of burial and associated heating in Permian\u2013Triassic age rocks, the initially unexpected absence of IDP-hosted ^3He likely indicates thermally induced diffusive loss. Indeed one of the key sections (Graphite Peak, Antarctica) from which extraterrestrial ^3He has been reported at and near the Permian\u2013Triassic boundary has been sufficiently heated that the reported preservation of extraterrestrial helium, in both IDPs and fullerenes, is inexplicable. Recent contamination provides a plausible explanation for extraterrestrial ^3He in these samples.\nWhile no extraterrestrial 3He was detected at Opal Creek, there is a sharp increase in nucleogenic ^3He very close to or at the Permian\u2013Triassic boundary. This presumably arises from the major lithologic change at this time, from cherts in the Permian to shales and siltstones in the Triassic. Increased nucleogenic ^3He is associated with increases in both lithium and organic carbon content into the Triassic. Either the production rate or the retention of this ^3He is higher in the shales and siltstones than in the cherts. Care must be taken to eliminate such artifacts before interpreting changes in ^3He concentration in terms of fluctuations in the delivery of ^3He from space.", "date": "2005-12-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "240", "number": "2", "publisher": "Elsevier", "pagerange": "265-275", "id_number": "CaltechAUTHORS:20121119-110648994", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121119-110648994", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA Astrobiology Institute" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2005.09.054", "resource_type": "article", "pub_year": "2005", "author_list": "Farley, K. A.; Ward, P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/g1tkk-srx67", "eprint_id": 20872, "eprint_status": "archive", "datestamp": "2023-08-19 16:16:35", "lastmod": "2023-10-20 23:32:31", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clark-M-K", "name": { "family": "Clark", "given": "Marin K." }, "orcid": "0000-0002-6141-8422" }, { "id": "Maheo-G", "name": { "family": "Maheo", "given": "Gweltaz" } }, { "id": "Saleeby-J-B", "name": { "family": "Saleeby", "given": "Jason" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "The non-equilibrium landscape of the southern Sierra Nevada, California", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2005 Geological Society of America.\n\nManuscript received 15 March 2005;\naccepted 4 July 2005.\nThis work was supported by National Science\nFoundation grants EAR-0230383 (Saleeby and Farley),\nEAR-0105981 (Farley), and EAR-0087347 (Saleeby); the\nTexaco Prize Postdoctoral Fellowship (Clark); and the\nCaltech Tectonics Observatory. We thank L. Hedges and\nC. Paine for analytical assistance, and T. Gannon (Clear\nCreek Systems, Inc., Bakersfield, California) for flight time\nand field assistance. Reviews provided by M. Brandon, S.\nBrocklehurst, D. Malmon, M. Oskin, and G. Stock greatly\nimproved this manuscript.", "abstract": "The paleoelevation of the Sierra\nNevada, California, is important to\nour understanding of the Cenozoic\ngeodynamic evolution of the North\nAmerica\u2013Pacific plate boundary,\nand the current debate is fueled by\ndata that argue for conflicting elevation\nhistories. The non-equilibrium\nor transient landscape of the Sierra\nNevada contains information about\nboth past and present controls on the\ntopography of the range. Using geomorphology\nand thermochronometry,\ntwo parts of the landscape of different\ngeodynamic significance and age\ncan be identified: (1) a long-lived,\nslowly eroding low-relief highland or\nrelict landscape, which we relate to\na period of lower relief and elevation\nfrom 80\u201332 Ma; and (2) younger, rapidly-\nincising river gorges created by at\nleast two stages of elevation and relief\nincrease since 32 Ma. Our data argue\nfor moderate range elevation of ~1500\nm at the cessation of arc magmatism in\nLate Cretaceous time, followed by two\nevents at between 32 and 3.5 Ma and\nsince 3.5 Ma that increased the range\nelevation to the 4000 m observed elevation\ntoday.", "date": "2005-09", "date_type": "published", "publication": "GSA Today", "volume": "15", "number": "9", "publisher": "Geological Society of America", "pagerange": "4-10", "id_number": "CaltechAUTHORS:20101118-074345207", "issn": "1052-5173", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101118-074345207", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0230383" }, { "agency": "NSF", "grant_number": "EAR-0105981" }, { "agency": "NSF", "grant_number": "EAR-0087347" }, { "agency": "Texaco Prize Postdoctoral Fellowship" }, { "agency": "Caltech Tectonics Observatory" } ] }, "other_numbering_system": { "items": [ { "id": "24", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "resource_type": "article", "pub_year": "2005", "author_list": "Clark, Marin K.; Maheo, Gweltaz; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/c882x-1wm19", "eprint_id": 35577, "eprint_status": "archive", "datestamp": "2023-08-22 03:36:49", "lastmod": "2023-10-20 19:10:34", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "David L." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Diffusion kinetics of proton-induced ^(21)Ne, ^3He, and ^4He in quartz", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2005 Elsevier Ltd. Received June 2, 2004; accepted in revised form November 2, 2004. Associate editor: R. Wieler. We thank G. Rossman for providing the quartz sample, D. Burnett for helpful input, and J. Sisterson and E. Cascio for their expertise with the irradiation. The reviews and comments of Rainer Wieler, Tom Trull, Tibor Dunai and an anonymous referee led to improvement of the manuscript and the additional low dose experiment. This work was supported by the National Science Foundation and by a N.S.F. Graduate Research Fellowship to D.L.S.", "abstract": "A natural quartz sample free of mineral and fluid inclusions was irradiated with a 200 MeV proton beam to produce spallogenic ^(21)Ne, ^3He and ^4He. Temperature-dependent diffusivities of these three nuclides were then determined simultaneously by high precision stepped-heating and noble gas mass spectrometry. The outward mobility of proton-induced nuclides reflects diffusion through the quartz lattice. In the studied range of 70 to 400\u00b0C the helium diffusion coefficients exceed those of neon by 5\u20137 orders of magnitude. The implied diffusion parameters E_a = 153.7 \u00b1 1.5 (kJ/mol) and ln(D_o/a^2) = 15.9 \u00b1 0.3 (ln(s^(\u22121))) and E_a = 84.5 \u00b1 1.2 (kJ/mol) and ln(D_o/a^2) = 11.1 \u00b1 0.3 (ln(s^(\u22121))) for proton-induced ^(21)Ne and ^3He, respectively, indicate that cosmogenic neon will be quantitatively retained in inclusion-free quartz at typical Earth surface temperatures whereas cosmogenic helium will not. However, the neon diffusion parameters also indicate that diffusive loss needs to be considered for small (<1 mm) quartz grains that have experienced elevated temperatures. Since natural quartz often contains fluid inclusions which may enhance noble gas retentivity, these parameters likely represent an end-member case of purely solid-state diffusion. The \u223c70 kJ/mol higher activation energy for neon diffusion compared to helium diffusion likely represents an energy barrier related to its \u223c13% greater diameter and provides a fundamental constraint with which to test theories of solid state diffusion. The diffusion parameters for proton-induced ^4He are indistinguishable from those for ^3He, providing no evidence for the commonly expected inverse square root of the mass diffusion relationship between isotopes. We also find preliminary indication that increased exposure to radiation may enhance neon and helium retentivity in quartz at low temperatures.", "date": "2005-05-01", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "69", "number": "9", "publisher": "Elsevier", "pagerange": "2349-2359", "id_number": "CaltechAUTHORS:20121120-135218509", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-135218509", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" }, { "agency": "NSF Graduate Research Fellowship" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2004.11.002", "resource_type": "article", "pub_year": "2005", "author_list": "Shuster, David L. and Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/rzd6q-62488", "eprint_id": 35576, "eprint_status": "archive", "datestamp": "2023-08-22 03:09:53", "lastmod": "2023-10-20 19:10:28", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "David L." } }, { "id": "Vasconcelos-P-M", "name": { "family": "Vasconcelos", "given": "Paulo M." } }, { "id": "Heim-J-A", "name": { "family": "Heim", "given": "Jonathan A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Weathering geochronology by (U-Th)/He dating of goethite", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2005 Elsevier Ltd. Received March 19, 2004; accepted in revised form July 30, 2004. Associate editor: T. M. Harrison. We thank L. Hedges and C. Paine for sample\npreparation and J. Sisterson and E. Cascio for their expertise with the proton irradiation. We thank P. Reiners and an anonymous reviewer for their constructive comments on the manuscript. This work was supported by the National Science Foundation and UQ-AGES (University of Queensland Argon Geochronology in Earth Sciences) Laboratories.\nD.L.S. was supported by a N.S.F. Graduate Research Fellowship.", "abstract": "Nine samples of supergene goethite (FeOOH) from Brazil and Australia were selected to test the suitability of this mineral for (U-Th)/He dating. Measured He ages ranged from 61 to 8 Ma and were reproducible to better than a few percent despite very large variations in [U] and [Th]. In all samples with internal stratigraphy or independent age constraints, the He ages corroborated the expected relationships. These data demonstrate that internally consistent He ages can be obtained on goethite, but do not prove quantitative ^4He retention. To assess possible diffusive He loss, stepped-heating experiments were performed on two goethite samples that were subjected to proton irradiation to produce a homogeneous distribution of spallogenic ^3He. The ^3He release pattern indicates the presence of at least two diffusion domains, one with high helium retentivity and the other with very low retentivity at Earth surface conditions. The low retentivity domain, which accounts for \u223c 5% of ^3He, contains no natural ^4He and may represent poorly crystalline or intergranular material which has lost all radiogenic ^4He by diffusion in nature. Diffusive loss of ^3He from the high retentivity domain is independent of the macroscopic dimensions of the analyzed polycrystalline aggregate, so probably represents diffusion from individual micrometer-size goethite crystals. The ^4He/^3He evolution during the incremental heating experiments shows that the high retentivity domain has retained 90%\u201395% of its radiogenic helium. This degree of retentivity is in excellent agreement with that independently predicted from the helium diffusion coefficients extrapolated to Earth surface temperature and held for the appropriate duration. Considering both the high and low retentivity domains, these data indicate that one of the samples retained 90% of its radiogenic ^4He over 47.5 Ma and the other retained 86% over 12.3 Ma. Thus while diffusive-loss corrections to supergene goethite He ages are required, these initial results indicate that the corrections are not extremely large and can be rigorously quantified using the proton-irradiation ^4He/^3He method.", "date": "2005-02-01", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "69", "number": "3", "publisher": "Elsevier", "pagerange": "659-673", "id_number": "CaltechAUTHORS:20121120-133722013", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-133722013", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" }, { "agency": "University of Queensland Argon Geochronology in Earth Sciences (UQ-AGES)" }, { "agency": "NSF Graduate Research Fellowship" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.gca.2004.07.028", "resource_type": "article", "pub_year": "2005", "author_list": "Shuster, David L.; Vasconcelos, Paulo M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/2a3md-68122", "eprint_id": 35572, "eprint_status": "archive", "datestamp": "2023-08-22 03:05:09", "lastmod": "2023-10-20 19:10:03", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "McDowell-F-W", "name": { "family": "McDowell", "given": "Fred W." } }, { "id": "McIntosh-W-C", "name": { "family": "McIntosh", "given": "William C." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "A precise ^(40)Ar\u2013^(39)Ar reference age for the Durango apatite (U\u2013Th)/He and fission-track dating standard", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Geochronology; ^(40)Ar\u2013^(39)Ar; (U\u2013Th)/He; Apatite; Durango, Mexico", "note": "\u00a9 2004 Elsevier B.V. Received 31 March 2004; accepted 7 October 2004. It is obvious that this contribution would not have been possible without heavy reliance upon the\nresearch projects of three Masters students. Although the essence of those studies has been published previously, Richard Keizer, James Lyons and Eric Swanson are deserving of renewed recognition for their fine work. Keizer and Paul Guenther also provided help with the K\u2013Ar dating. The (U\u2013Th)/He age determinations were supported by NSF EAR\n0105981. Comments by Lyons, Swanson, Mark Cloos, Todd Housh and Richard Ketcham have greatly improved this manuscript. Lyons also provided help in preparing Fig. 1. We thank Mike Villenueva and Joann Wartho for their helpful reviews. [PD]", "abstract": "The distinctive Durango apatite is widely distributed as a reference material for mineralogy, geochemistry and thermochronology. The apatite occurs within the Cerro de Mercado open-pit iron mine, located in the northern portion of Durango City, Mexico. It is largely confined to vugs and open fractures within the lower portion of the ore deposit. Apatite and iron ore formed in situ and concurrently along with emplacement of small felsic intrusions along the southern margin of the Chupaderos caldera complex. This activity occurred between eruptions of two major ignimbrites from the caldera complex. Four single-crystal sanidine-anorthoclase ^(40)Ar\u2013^(39)Ar ages from these ignimbrites and from a conformable older unit have been used to compute a reference age of 31.44\u00b10.18 Ma (2\u03c3) for the apatite itself. Four additional multi-crystal measurements are in general agreement with this age. Also in agreement are a set of 24 (U\u2013Th\u2013Sm)/He ages recently determined directly on the apatite, which have a mean of 31.02\u00b11.01 Ma 1\u03c3, with a standard error (S.E.) of \u00b10.22 Ma.", "date": "2005-01-25", "date_type": "published", "publication": "Chemical Geology", "volume": "214", "number": "3-4", "publisher": "Elsevier", "pagerange": "249-263", "id_number": "CaltechAUTHORS:20121120-130529682", "issn": "0009-2541", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-130529682", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0105981" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.chemgeo.2004.10.002", "resource_type": "article", "pub_year": "2005", "author_list": "McDowell, Fred W.; McIntosh, William C.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/cprd1-wwn14", "eprint_id": 1103, "eprint_status": "archive", "datestamp": "2023-08-22 02:52:26", "lastmod": "2023-10-13 22:37:11", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Keller-R-A", "name": { "family": "Keller", "given": "R. A." } }, { "id": "Graham-D-W", "name": { "family": "Graham", "given": "D. W." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Duncan-R-A", "name": { "family": "Duncan", "given": "R. A." } }, { "id": "Lupton-J-E", "name": { "family": "Lupton", "given": "J. E." } } ] }, "title": "Cretaceous-to-recent record of elevated 3He/4He along the Hawaiian-Emperor volcanic chain", "ispublished": "pub", "full_text_status": "public", "keywords": "Hawaiian-Emperor chain; helium; MORB; 1040 Geochemistry: Isotopic composition/chemistry; 8124 Tectonophysics: Earth's interior\u2014composition and state (1212); 9355 Information Related to Geographic Region: Pacific Ocean", "note": "Copyright 2004 by the American Geophysical Union. \n\nReceived: 6 April 2004; Revised: 8 September 2004; Accepted: 26 October 2004; Published: 31 December 2004. \n\nWe are grateful to Asish Basu for use of unpublished helium data and to Marcel Regelous for assistance in selecting the Suiko Seamount samples. We are also grateful to Emily Van Ark and Jian Lin for sharing their plume flux calculations prior to publication. Analytical work on the ODP and DSDP samples was supported by NSF funds managed through the JOI/USSSP. The helium isotope laboratory at the Newport PMEL is supported by the NOAA Vents Program.", "abstract": "Helium isotopes are a robust geochemical tracer of a primordial mantle component in hot spot volcanism. The high 3He/4He (up to 35 RA, where RA is the atmospheric 3He/4He ratio of 1.39 \u00d7 10\u22126) of some Hawaiian Island volcanism is perhaps the classic example. New results for picrites and basalts from the Hawaiian-Emperor seamount chain indicate that the hot spot has produced high 3He/4He lavas for at least the last 76 million years. Picrites erupted at 76 Ma have 3He/4He (10\u201314 RA), which is at the lower end of the range for the Hawaiian Islands but still above the range of modern mid-ocean ridge basalt (MORB; 6\u201310 RA). This was at a time when hot spot volcanism was occurring on thin lithosphere close to a spreading ridge and producing lava compositions otherwise nearly indistinguishable from MORB. After the hot spot and spreading center diverged during the Late Cretaceous, the hot spot produced lavas with significantly higher 3He/4He (up to 24 RA). Although 3He/4He ratios stabilized at relatively high values by 65 Ma, other chemical characteristics such as La/Yb and 87Sr/86Sr did not reach and stabilize at Hawaiian-Island-like values until ~45 Ma. Our limited 3He/4He record for the Hawaiian hot spot shows a poor correlation with plume flux estimates (calculated from bathymetry and residual gravity anomalies [Van Ark and Lin, 2004]). If 3He is a proxy for the quantity of primordial mantle material within the plume, then the lack of correlation between 3He/4He and calculated plume flux suggests that variation in primordial mantle flux is not the primary factor controlling total plume flux.", "date": "2004-12-31", "date_type": "published", "publication": "Geochemistry, Geophysics, Geosystems", "volume": "5", "number": "12", "publisher": "American Geophysical Union", "pagerange": "2004GC000739", "id_number": "CaltechAUTHORS:KELggg04", "issn": "1525-2027", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:KELggg04", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2004GC000739", "primary_object": { "basename": "KELggg04.pdf", "url": "https://authors.library.caltech.edu/records/cprd1-wwn14/files/KELggg04.pdf" }, "resource_type": "article", "pub_year": "2004", "author_list": "Keller, R. A.; Graham, D. W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3bmhf-wsn08", "eprint_id": 35468, "eprint_status": "archive", "datestamp": "2023-08-22 02:45:58", "lastmod": "2023-10-20 16:22:43", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Koeberl-C", "name": { "family": "Koeberl", "given": "Christian" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Peucker-Ehrenbrink-B", "name": { "family": "Peucker-Ehrenbrink", "given": "Bernhard" }, "orcid": "0000-0002-3819-992X" }, { "id": "Sephton-M-A", "name": { "family": "Sephton", "given": "Mark A." } } ] }, "title": "Geochemistry of the end-Permian extinction event in Austria and Italy: No evidence for an extraterrestrial component", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Permian-Triassic boundary; impacts; mass extinctions; Os isotopes; He isotopes", "note": "\u00a9 2004 Geological Society of America.\nManuscript received 23 June 2004.\nRevised manuscript received 30 August 2004.\nManuscript accepted 30 August 2004.\nThis work was supported by the Austrian Science\nFoundation, project Y58-GEO, the United Kingdom\nParticle Physics and Astronomy Research Council\n(PPARC), and the U.S. National Science Foundation.\nPeucker-Ehrenbrink thanks T. Abbruzzese and D.\nSchneider (Woods Hole Oceanographic Institution Inductively\nCoupled Plasma Facility) for analytical assistance.\nWe are grateful to G. Retallack, J. Smit, and P.\nWignall for constructive reviews.", "abstract": "The end-Permian mass extinction (251 Ma) was the largest in Earth's history, and the great extent of biospheric perturbation is recorded as dramatic shifts in carbon isotope ratios of sedimentary materials. Both terrestrial and extraterrestrial events are commonly invoked as causative mechanisms for the crisis, and the primary reason for the event remains the subject of controversy. Geochemical indicators sensitive to the influence of extraterrestrial material involve platinum group elements and osmium and helium isotope ratios. Analyses of extinction levels in two sections from Austria and Italy reveal no evidence of an extraterrestrial impact. The end-Permian crisis, it appears, was a homegrown catastrophe.", "date": "2004-12", "date_type": "published", "publication": "Geology", "volume": "32", "number": "12", "publisher": "Geological Society of America", "pagerange": "1053-1056", "id_number": "CaltechAUTHORS:20121114-161332395", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121114-161332395", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Austrian Science Foundation", "grant_number": "Y58-GEO" }, { "agency": "Particle Physics and Astronomy Research Council (PPARC)" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/G20907.1", "resource_type": "article", "pub_year": "2004", "author_list": "Koeberl, Christian; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/1xcwh-zaa76", "eprint_id": 35540, "eprint_status": "archive", "datestamp": "2023-08-22 02:42:29", "lastmod": "2023-10-20 19:07:02", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Burnard-P-G", "name": { "family": "Burnard", "given": "Pete" } }, { "id": "Graham-D", "name": { "family": "Graham", "given": "David" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Ken" }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Fractionation of noble gases (He, Ar) during MORB mantle\n melting: a case study on the Southeast Indian Ridge", "ispublished": "pub", "full_text_status": "public", "keywords": "noble gas; degassing; diffusion; mid-ocean ridge basalt; Southeast Indian Ridge; mantle melting", "note": "\u00a9 2004 Elsevier B.V. Received 21 January 2004; received in revised form 22 April 2004; accepted 18 August 2004. Available online 13 October 2004. Editor: B. Wood. This work was supported by the Marine Geology and Geophysics Division of the National Science Foundation (OCE99-12359 and OCE99-11418). Dave Christie (OSU) helped with sample selection and shared major and trace element data. The authors are extremely grateful for the thorough and insightful reviews by Dave Hilton, Manuel Moreira, Phillipe\nSarda and an anonymous reviewer.\n\nSupplemental Material - mmc1.doc
Supplemental Material - mmc2.doc
", "abstract": "New measurements of the He, Ar and CO_2 abundances trapped in basaltic glasses from the Southeast Indian Ridge (SEIR) show that volatile concentrations in the SEIR magmas were controlled by fractional degassing. Fractionation between volatile species is consistent with their solubilities in silicate melts. As a result, there are linear relationships between (for example) ln(^4He/^(40)Ar^*) vs. ln[^(40)Ar^*] and between ln(^4He/^(40)Ar^*) vs. ln(^(40)Ar^*/CO_2) (where ^(40)Ar^* is the ^(40)Ar corrected for atmospheric contributions). The slopes of these correlations permit the relative He/Ar and Ar/CO_2 solubilities to be estimated; these are generally consistent with experimentally determined noble gas solubilities in basaltic melts.\nHowever, there are systematic differences in the degassing trajectories. For example, in a plot of ln(^4He/^(40)Ar^*) vs. ln(^(40)Ar^*/CO_2), samples from the deepest portions of the ridge consistently plot at lower ^4He/^(40)Ar^* for a given ^(40)Ar^*/CO_2, compared to shallower sections of ridge. These variations in ^4He/^(40)Ar^* likely reflect variations in He/Ar in the primary melt, i.e. their relative abundances prior to degassing. We estimated the variation in ^4He/^(40)Ar^* in the initial melts (i.e. the ^4He/^(40)Ar^* prior to degassing) by extrapolating the degassing trend to a constant mantle-like ^(40)Ar^*/CO_2 ratio and assuming that the relative He\u2013Ar\u2013CO_2 solubilities do not vary between samples. The ^4He/^(40)Ar^* corrected for degassing in this manner varies by a factor \u224810 and correlates positively with the ^3He/^4He ratio.\nIt is possible that the correlation between \"degassing corrected\" ^4He/^(40)Ar^* ratios and the ^3He/^4He ratio results from preferential diffusion of ^3He relative to ^4He and of 4He relative to ^(40)Ar from the solid mantle into primary melts during melting. However, modeling this diffusive process fails to reproduce the comparatively large variations in ^3He/^4He found in the basalts; therefore, it seems likely that mantle heterogeneities, in combination with diffusive fractionation, resulted in coupled He isotope and He/Ar variations.", "date": "2004-11-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "227", "number": "3-4", "publisher": "Elsevier", "pagerange": "457-472", "id_number": "CaltechAUTHORS:20121119-104626471", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121119-104626471", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF Marine Geology and Geophysics Division", "grant_number": "OCE99-12359" }, { "agency": "NSF Marine Geology and Geophysics Division", "grant_number": "OCE99-11418" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2004.08.021", "primary_object": { "basename": "mmc1.doc", "url": "https://authors.library.caltech.edu/records/1xcwh-zaa76/files/mmc1.doc" }, "related_objects": [ { "basename": "mmc2.doc", "url": "https://authors.library.caltech.edu/records/1xcwh-zaa76/files/mmc2.doc" } ], "resource_type": "article", "pub_year": "2004", "author_list": "Burnard, Pete; Graham, David; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/kvyfp-ssa42", "eprint_id": 37131, "eprint_status": "archive", "datestamp": "2023-08-19 14:33:12", "lastmod": "2023-10-23 16:59:46", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Renne-Paul-R", "name": { "family": "Renne", "given": "Paul R." }, "orcid": "0000-0003-1769-5235" }, { "id": "Melosh-H-Jay", "name": { "family": "Melosh", "given": "H. Jay" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Reimold-W-Uwe", "name": { "family": "Reimold", "given": "W. Uwe" } }, { "id": "Koeberl-Christian", "name": { "family": "Koeberl", "given": "Christian" } }, { "id": "Rampino-Michael-R", "name": { "family": "Rampino", "given": "Michael R." } }, { "id": "Kelly-Simon-P", "name": { "family": "Kelly", "given": "Simon P." } }, { "id": "Ivanov-Boris-A", "name": { "family": "Ivanov", "given": "Boris A." } } ] }, "title": "Is Bedout an Impact Crater? Take 2", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2004 American Association for the Advancement of Science.", "abstract": "In their Research Article \"Bedout: a possible end-Permian impact crater offshore of northwestern Australia,\" L. Becker et al. report having identified a buried impact structure, which they link to the Permian-Triassic mass extinction (4 June, p. 1469; published online 13 May; 10.1126/science.1093925). Becker et al. have scarcely extended the suggestion made by Australian petroleum workers (in industry trade journals). Our scrutiny of the alleged evidence indicates that there is no substantiation that this alleged structure is an impact crater. The gravity map (fig. 11) actually highlights the differences between Bedout and confirmed impact structures. There is actually no crater defined by the geophysical data, only a noncircular high in the seismic data, claimed to be a \"central uplift.\" In comparison, the central uplift feature of a large impact structure, such as the 250- to 300-km-diameter Vredefort Structure, would reveal a significant central positive gravity anomaly due to the uplift of relatively denser mid- to lower crustal material. The highly altered rocks described by Becker et al. as impact products strongly resemble volcanic breccias and lack impact diagnostic textures. No true shock features are described from any of the samples. No mineralogical or geochemical evidence is provided that the purported \"diaplectic glass\" or \"maskelynite\" are indeed glasses, and mineral chemical information is missing. The \"shock features\" claimed to be presented in quartz grains from \"ejecta horizons\" (which remain of uncertain stratigraphic relation either to the alleged Bedout feature or to the end-Permian extinction) do not show any of the characteristics of unambiguous shocked minerals.", "date": "2004-10-22", "date_type": "published", "publication": "Science", "volume": "306", "number": "5696", "publisher": "American Association for the Advancement of Science", "pagerange": "610-611", "id_number": "CaltechAUTHORS:20130226-090801509", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130226-090801509", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.306.5696.610", "resource_type": "article", "pub_year": "2004", "author_list": "Renne, Paul R.; Melosh, H. Jay; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/wdrh4-ft877", "eprint_id": 35565, "eprint_status": "archive", "datestamp": "2023-08-22 02:11:02", "lastmod": "2023-10-20 19:09:04", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Stockli-D-F", "name": { "family": "Stockli", "given": "Daniel F." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Empirical constraints on the titanite (U\u2013Th)/He partial\n retention zone from the KTB drill hole", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Titanite; (U\u2013Th)/He; Thermochronology; KTB; Borehole; Calibration", "note": "\u00a9 2004 Elsevier B.V. Received 17 February 2003; accepted 8 March 2004. This work was supported by the National Science\nFoundation and by a Texaco postdoctoral fellowship\naward to D. Stockli and a David and Lucille Packard\nFoundation fellowship award to K. Farley. We are\ngrateful to R. Jonckheere and G. Wagner for providing\nKTB titanite separates. We also thank L. Hedges for\nassistance in the Caltech Noble Gas laboratory and L.\nStockli for assistance with SEM inclusion imaging at\nUCLA. Helpful reviews by A. Warnock and P. Zeitler\nimproved the manuscript. [PD]", "abstract": "We analyzed (U\u2013Th)/He ages of titanite from both the initial pilot hole (4 km depth) and the main drill-hole (9 km depth) of the German Continental Deep Drilling Project (KTB), to empirically evaluate the titanite (U\u2013Th)/He partial retention zone (HePRZ) and laboratory helium diffusion data. Laser (U\u2013Th)/He ages on single titanite fragments from the KTB drill hole, uncorrected for \u03b1 emission, range from \u223c94 to \u223c2 Ma with reproducibility better than \u00b19%. Nearly invariant titanite (U\u2013Th)/He ages, concordant with reported apatite fission track data, suggest that rocks from the upper \u223c3 km of the KTB drill hole rapidly cooled from temperatures >200 to <110 \u00b0C between \u223c75 and 85 Ma, followed by protracted cooling. Below \u223c3 km, mean titanite (U\u2013Th)/He ages decrease systematically with increasing borehole depth and down-hole temperature in a pattern similar to the titanite HePRZ predicted on the basis of laboratory-determined He diffusivities. Our results demonstrate that experimental titanite He diffusion data are applicable in the natural setting and that titanite (U\u2013Th)/He thermochronometry provides a means to reliably reconstruct and quantify thermal histories between \u223c100 and 180 \u00b0C, bridging the temperature ranges constrained by other techniques such as ^(40)Ar/^(39)Ar K-feldspar multi-diffusion domain modeling (350\u2013150 \u00b0C) and apatite fission track dating (<110 \u00b0C).", "date": "2004-07-16", "date_type": "published", "publication": "Chemical Geology", "volume": "207", "number": "3-4", "publisher": "Elsevier", "pagerange": "223-236", "id_number": "CaltechAUTHORS:20121120-111334016", "issn": "0009-2541", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-111334016", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" }, { "agency": "Texaco Postdoctoral Fellowship" }, { "agency": "David and Lucile Packard Foundation Fellowship" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.chemgeo.2004.03.002", "resource_type": "article", "pub_year": "2004", "author_list": "Stockli, Daniel F. and Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/htpk3-mv256", "eprint_id": 1095, "eprint_status": "archive", "datestamp": "2023-08-22 01:51:15", "lastmod": "2023-10-13 22:36:53", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Workman-Rhea-K", "name": { "family": "Workman", "given": "R. K." } }, { "id": "Hart-Stanley-R", "name": { "family": "Hart", "given": "S. R." } }, { "id": "Jackson-Matthew-G", "name": { "family": "Jackson", "given": "M." } }, { "id": "Regelous-M", "name": { "family": "Regelous", "given": "M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Blusztajn-Jerzy-S", "name": { "family": "Blusztajn", "given": "J." }, "orcid": "0000-0002-5475-1948" }, { "id": "Kurz-Mark-D", "name": { "family": "Kurz", "given": "M." }, "orcid": "0000-0003-1745-2356" }, { "id": "Staudigel-H", "name": { "family": "Staudigel", "given": "H." } } ] }, "title": "Recycled metasomatized lithosphere as the origin of the Enriched Mantle II (EM2) end-member: Evidence from the Samoan Volcanic Chain", "ispublished": "pub", "full_text_status": "public", "keywords": "EM2; Samoa; metasomatized lithosphere; Sr-Nd-Pb-He-Os isotopes; hot spot chain; Vailulu'u Volcano; 1040 Geochemistry: Isotopic composition/chemistry; 8121 Tectonophysics: Dynamics, convection currents and mantle plumes; 5480 Planetology: Solid Surface Planets: Volcanism", "note": "Copyright 2004 by the American Geophysical Union. \n\nReceived: 21 August 2003; Revised: 7 January 2004; Accepted: 22 January 2004; Published: 27 April 2004 \n\nWithout Alberto Saal, we likely would have done none of this. He once printed an earthquake map that identified activity in a place that shouldn't have any. This led to the 1999 AVON 3 cruise, and discovery of active volcanism at Vailulu'u volcano. It also led to the dredging of tons of basalts that are the backbone of this paper. We thank Alberto for all of this, especially his help on the AVON 3 cruise and his help during fieldwork on Ta'u Island. Anthony Koppers was enormously helpful with data and sample processing during and following the AVON 3 cruise. We are also grateful to the captain and crew of the R/V Melville, along with the student volunteers, for catching and processing these tons of rocks. We thank Francis Albar\u00e8de for access to the Lyon ICP/MS, and to Ken Sims and Sylvain Pichatt for their 24/7 efforts there in running many Pb isotope analyses. We thank Steve Galer and Wafa Abouchami for many tutorials in implementing the Mainz Pb chemistry at WHOI. The output of high-precision Pb data from the WHOI NEPTUNE is due largely to Lary Ball's skill and tenacity; our many thanks. Megan Coetzee's work on the Western Samoan seamounts, during a summer internship at WHOI, provided enthusiastic counterpoint to our work on the eastern volcanoes. We acknowledge NSF support, through grant OCE-9819038 (SRH and HS), and EAR-0125917 (SRH). Very constructive reviews were provided by Yaoling Niu and Rick Carlson. Finally, our gratitude to Jim Natland, for his generosity in sharing Samoan rocks, data and ideas, and for being an enduringly collegial provocateur. M. Regelous thanks A. Greig, Y. Niu, J. I. Wendt, W. Abouchami, S. Galer, C. Coath and C. Counsell for help and advice with the analytical measurements, and Warren Jopling of Safua Hotel for sharing his geological knowledge of Savai'i.", "abstract": "An in-depth Sr-Nd-Pb-He-Os isotope and trace element study of the EMII-defining Samoan hot spot lavas leads to a new working hypothesis for the origin of this high 87Sr/86Sr mantle end-member. Systematics of the Samoan fingerprint include (1) increasing 206Pb/204Pb with time - from 18.6 at the older, western volcanoes to 19.4 at the present-day hot spot center, Vailulu'u Seamount, (2) en-echelon arrays in 206Pb/204Pb \u2013 208Pb/204Pb space which correspond to the two topographic lineaments of the 375 km long volcanic chain \u2013 this is much like the Kea and Loa Trends in Hawai'i, (3) the highest 87Sr/86Sr (0.7089) of all oceanic basalts, (4) an asymptotic decrease in 3He/4He from 24 RA [Farley et al., 1992] to the MORB value of 8 RA with increasing 87Sr/86Sr, and (5) mixing among four components which are best described as the \"enriched mantle\", the depleted FOZO mantle, the (even more depleted) MORB Mantle, and a mild HIMU (high 238U/204Pb) mantle component. A theoretical, \"pure\" EMII lava composition has been calculated and indicates an extremely smooth trace element pattern of this end-member mantle reservoir. The standard recycling model (of ocean crust/sediment) fails as an explanation for producing Samoan EM2, due to these smooth spidergrams for EM2 lavas, low 187Os/188Os ratios and high 3He/4He (>8 RA). Instead, the origin of EM2 has been modeled with the ancient formation of metasomatised oceanic lithosphere, followed by storage in the deep mantle and return to the surface in the Samoan plume.", "date": "2004-04-27", "date_type": "published", "publication": "Geochemistry, Geophysics, Geosystems", "volume": "5", "number": "4", "publisher": "American Geophysical Union", "pagerange": "2003GC000623", "id_number": "CaltechAUTHORS:WORggg04", "issn": "1525-2027", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:WORggg04", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2003GC000623", "primary_object": { "basename": "WORggg04.pdf", "url": "https://authors.library.caltech.edu/records/htpk3-mv256/files/WORggg04.pdf" }, "resource_type": "article", "pub_year": "2004", "author_list": "Workman, R. K.; Hart, S. R.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/59wv0-w5440", "eprint_id": 35538, "eprint_status": "archive", "datestamp": "2023-08-22 01:34:59", "lastmod": "2023-10-20 19:06:51", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Belton-D-X", "name": { "family": "Belton", "given": "D. X." } }, { "id": "Brown-R-W", "name": { "family": "Brown", "given": "R. W." } }, { "id": "Kohn-B-P", "name": { "family": "Kohn", "given": "B. P." } }, { "id": "Fink-D", "name": { "family": "Fink", "given": "D." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Quantitative resolution of the debate over antiquity of the\n central Australian landscape: implications for the tectonic and geomorphic stability of cratonic interiors", "ispublished": "pub", "full_text_status": "restricted", "keywords": "landscape evolution; denudation; apatite; fission track analysis; cosmogenic radionuclides; Davenport Range; Alice Springs Orogeny; Australia", "note": "\u00a9 2004 Elsevier B.V. Received 11 May 2003; received in revised form 7 July 2003; accepted 4 December 2003. This work was funded by the Australian Research Council, the Australian Institute of Nuclear Science and Engineering (AINSE) and the Australian Geodynamics Cooperative Research\nCentre. D.X.B. was supported by an AINSE postgraduate\nscholarship and R.W.B. acknowledges the support of a University of Melbourne Research Career Establishment Grant. We extend our thanks to Alistair Stewart for field information and encouragement. Thanks to Derek Fabel\nand Kerry Gallagher for critically reviewing the\nmanuscript.[BW]", "abstract": "We report the first measure of long- (\u223c100 Myr) and short- (\u223c1 Myr) term denudation rates from key geologically stable landforms in the Davenport Range, central Australia. These landforms have previously been assigned a Cambrian age, which arguably places them amongst the oldest persistent landforms on the continent, if not on Earth. Our results from combined apatite fission track thermochronology and in situ cosmogenic radionuclide analyses using ^(10)Be and ^(26)Al show that while average exhumation rates are low, the denudation history for this cratonic region is incompatible with extreme, sub-aerial longevity and long-term tectonic and geomorphic stability. Our revised model for the landscape evolution of this region is consistent with one of maximum burial prior to and during the Mesozoic, followed by a phase of kilometre-scale exhumation that was largely complete by the beginning of the Cainozoic. We suggest that a similar process of burial and exhumation has probably been responsible for the sub-aerial preservation of seemingly ancient landforms elsewhere in Australia.", "date": "2004-02-28", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "219", "number": "1-2", "publisher": "Elsevier", "pagerange": "21-34", "id_number": "CaltechAUTHORS:20121119-103337376", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121119-103337376", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Australian Research Council" }, { "agency": "Australian Institute of Nuclear Science and Engineering (AINSE)" }, { "agency": "Australian Geodynamics Cooperative Research" }, { "agency": "Australian Institute of Nuclear Science and Engineering (AINSE) postgraduate scholarship" }, { "agency": "University of Melbourne Research Career Establishment grant" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(03)00705-2", "resource_type": "article", "pub_year": "2004", "author_list": "Belton, D. X.; Brown, R. W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/38ax0-p3523", "eprint_id": 35535, "eprint_status": "archive", "datestamp": "2023-08-22 01:26:40", "lastmod": "2023-10-20 19:06:34", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "David L." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Sisterson-J-M", "name": { "family": "Sisterson", "given": "Janet M." } }, { "id": "Burnett-D-S", "name": { "family": "Burnett", "given": "Donald S." }, "orcid": "0000-0001-9521-8675" } ] }, "title": "Quantifying the diffusion kinetics and spatial distributions of radiogenic ^4He in minerals containing proton-induced ^3He", "ispublished": "pub", "full_text_status": "restricted", "keywords": "helium; diffusion; thermochronometry; isotope; proton beam; (U\u2013Th)/He", "note": "\u00a9 2003 Elsevier B.V. Received 25 April 2003; received in revised form 18 June 2003; accepted 7 October 2003. We thank T. Schneider, S. Mukhopadhyay and E. Schauble for helpful input, L. Hedges for sample preparation and E. Cascio for his expertise with the irradiation, and two anonymous reviewers. This work was supported by the National\nScience Foundation and by a N.S.F. Graduate Research Fellowship to D.L.S.[BW]", "abstract": "Apatite, titanite and olivine samples were bombarded with a ~ 150 MeV proton beam to produce ~ 10^8 atoms/mg of spallation ^3He. High-precision stepped-heating experiments were then performed in which the artificial ^3He and, for apatite and titanite, the natural radiogenic ^4He were measured to characterize the diffusive behavior of each\nisotope. Helium-3 diffusion coefficients are in excellent agreement with concurrently and/or previously determined He\ndiffusion coefficients for each mineral. Our results indicate that proton-induced ^3He is uniformly distributed and that radiation damage associated with a proton fluence of ~ 5 x 10^(14) protons/cm^2 does not cause noticeable changes in ^4He diffusion behavior in at least apatite and titanite. Proton-induced ^3He can therefore be used to establish He diffusion coefficients in minerals with insufficient natural helium for analysis or those in which the natural ^4He distribution is inhomogeneous. In addition,step-heating ^4He/^3He analysis of a mineral with a uniform synthetic ^3He concentration provides a means by which a natural ^4He distribution can be determined.", "date": "2004-01-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "217", "number": "1-2", "publisher": "Elsevier", "pagerange": "19-32", "id_number": "CaltechAUTHORS:20121119-100729426", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121119-100729426", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" }, { "agency": "NSF Graduate Research Fellowship" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(03)00594-6", "resource_type": "article", "pub_year": "2004", "author_list": "Shuster, David L.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/z5qsp-tzp68", "eprint_id": 35537, "eprint_status": "archive", "datestamp": "2023-08-22 01:26:48", "lastmod": "2023-10-20 19:06:47", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "David L." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "^4He/^3He thermochronometry", "ispublished": "pub", "full_text_status": "restricted", "keywords": "helium; diffusion; thermochronometry; isotope; proton beam; (U\u2013Th)/He", "note": "\u00a9 2003 Elsevier B.V. Received 25 April 2003; received in revised form 18 June 2003; accepted 7 October 2003. We thank D. Burnett, T. Schneider, B. Weiss and F. Albar\u00e8de for helpful discussions and B. Watson and S. Kelley for reviews of the manuscript. We are grateful to T. Schneider for help with the inversion mathematics. This work was\nsupported by the National Science Foundation. D.L.S. was supported by a N.S.F. Graduate Research Fellowship.[BW]", "abstract": "Using classical diffusion theory, we present a mathematical technique for the determination of ^4He concentration profiles in minerals. This approach should prove useful for constraining the low-temperature cooling histories of individual samples and for correcting (U\u2013Th)/He ages for partial diffusive loss. The calculation assumes that the mineral of interest contains an artificially produced and uniform distribution of ^3He obtained by proton irradiation [Shuster et al., Earth Planet. Sci. Lett. 217 (2004) 19\u201332]. In minerals devoid of natural helium, this isotope allows measurement of He diffusion coefficients; in minerals with measurable radiogenic He, it permits determination of ^4He profiles arising during ingrowth and diffusion in nature. The ^4He profile can be extracted from stepwise degassing experiments in which the ^4He/^3He ratio is measured. The evolution of the ^4He/^3He ratio as a function of cumulative ^3He released can be compared with forward models to constrain the shape of the profile. Alternatively, we present a linear inversion that can be used to directly solve for the unknown ^4He distribution. The inversion incorporates a standard regularization technique to filter the influence of random measurement errors on the solution. Using either approach we show that stepwise degassing data can yield robust and high-resolution information on the ^4He profile. Profiles of radiogenic He are a sensitive function of the time\u2013Temperate (t\u2013T) path that a cooling sample experienced. Thus, by step heating a proton-irradiated sample it is possible to restrict the sample's acceptable t\u2013T paths. The sensitivity of this approach was explored by forward-modeling ^4He profiles resulting from a range of realistic t\u2013T paths, using apatite as an example. Results indicate that ^4He profiles provide rich information on t\u2013T paths, especially when the profiles are coupled with (U\u2013Th)/He cooling ages on the same sample. Samples that experienced only moderate diffusive loss have ^4He concentration profiles that are rounded at the edge but uniform in the core of the diffusion domain. Such profiles can be identified by nearly invariant ^4He/^3He ratios after the first few to few tens of percent of ^3He have been extracted by step heating. We show how such data can be used to correct (U\u2013Th)/He ages for partial diffusive loss.", "date": "2004-01-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "217", "number": "1-2", "publisher": "Elsevier", "pagerange": "1-17", "id_number": "CaltechAUTHORS:20121119-102114643", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121119-102114643", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" }, { "agency": "NSF Graduate Research Fellowship" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(03)00595-8", "resource_type": "article", "pub_year": "2004", "author_list": "Shuster, David L. and Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/kv5pc-jgb57", "eprint_id": 39533, "eprint_status": "archive", "datestamp": "2023-08-22 00:52:10", "lastmod": "2023-10-24 16:54:44", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Donelick-R", "name": { "family": "Donelick", "given": "R." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K." }, "orcid": "0000-0002-7846-7546" }, { "id": "O'Sullivan-P", "name": { "family": "O'Sullivan", "given": "P." } }, { "id": "Asimow-P-D", "name": { "family": "Asimow", "given": "P. D." }, "orcid": "0000-0001-6025-8925" } ] }, "title": "Experimental evidence concerning the pressure dependence of He diffusion and fission-track annealing kinetics in apatite", "ispublished": "pub", "full_text_status": "restricted", "abstract": "We offer this short note to document data we\nhave collected regarding the pressure\ndependence of He diffusion and fission-track\nannealing kinetics in apatite. This work is a\ndirect result of the provocative EPSL paper by\nWendt et al. (2002). Should their data stand, so\nshould many of their conclusions. For the record,\nwe have communicated constructively with Anke\nWendt and through her, her co-authors, and we\nhave the singular goal of better understanding\ntheir data and the issues raised in their paper.", "date": "2003-09", "date_type": "published", "publication": "On track: the newsletter of the international fission-track community", "volume": "13", "number": "2", "publisher": "International Fission-Track Community", "pagerange": "19-21", "id_number": "CaltechAUTHORS:20130723-131212011", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130723-131212011", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "resource_type": "article", "pub_year": "2003", "author_list": "Donelick, R.; Farley, K.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/tcfap-2ht93", "eprint_id": 33705, "eprint_status": "archive", "datestamp": "2023-08-22 00:51:05", "lastmod": "2023-10-18 20:35:16", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Donelick-R", "name": { "family": "Donelick", "given": "R." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K." }, "orcid": "0000-0002-7846-7546" }, { "id": "Asimow-P-D", "name": { "family": "Asimow", "given": "Paul D." }, "orcid": "0000-0001-6025-8925" }, { "id": "O'Sullivan-P", "name": { "family": "O'Sullivan", "given": "P." } } ] }, "title": "Pressure dependence of He diffusion and fission-track annealing kinetics in apatite?: Experimental results", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2003 Pergamon-Elsevier Science Ltd.", "abstract": "A number of preliminary experiments have been\nundertaken to test results reported by Wendt et al. (2002),\nconcerning the dependancy of pressure on fission track\nannealing in apatite, and which implied a similar dependancy\nfor He difusion in apatite.", "date": "2003-09", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "67", "number": "18", "publisher": "Elsevier", "pagerange": "A82", "id_number": "CaltechAUTHORS:20120830-104815559", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120830-104815559", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "resource_type": "article", "pub_year": "2003", "author_list": "Donelick, R.; Farley, K.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/z605z-2zf27", "eprint_id": 57317, "eprint_status": "archive", "datestamp": "2023-08-22 00:52:37", "lastmod": "2023-10-23 17:16:22", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "D. L." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Sisterson-J-M", "name": { "family": "Sisterson", "given": "J." } }, { "id": "Burnett-D-S", "name": { "family": "Burnett", "given": "D. S." }, "orcid": "0000-0001-9521-8675" } ] }, "title": "^4He/^3He thermochronometry", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2003 Elsevier B.V.", "abstract": "We demonstrate a technique that uses classical diffusion\ntheory to determine ^4He concentration profiles within\nminerals. This approach should prove useful for constraining\nthe low temperature cooling histories of individual samples\nand for correcting (U-Th)/He ages for partial diffusive loss. To validate the method, we investigated apatites with\nindependently constrained cooling histories. The minerals of\ninterest were irradiated with 220 MeV protons to induce an\nartificial distribution of spallation ^3He. Our results indicate that proton-induced ^3He is uniformly distributed and that radiation damage associated with a proton fluence of ~5x10^(14) protons/cm^2 does not cause noticeable changes in He diffusion behavior. Proton-induced ^3He can therefore be used to establish He diffusion coefficients in minerals with insufficient natural helium for analysis or those in which the natural ^4He distribution is inhomogeneous. In addition, step heating ^4He/^3He analysis of a mineral with a uniform synthetic ^3He concentration provides a means to constrain its natural ^4He distribution that arose during ingrowth and diffusion over geologic time.", "date": "2003-09", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "67", "number": "18", "publisher": "Elsevier", "pagerange": "A436-A436", "id_number": "CaltechAUTHORS:20150507-085549131", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150507-085549131", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0016-7037(03)00513-1", "resource_type": "article", "pub_year": "2003", "author_list": "Shuster, D. L.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/mm3mb-t6e20", "eprint_id": 35467, "eprint_status": "archive", "datestamp": "2023-08-22 00:40:04", "lastmod": "2023-10-20 16:22:32", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Stockli-D-F", "name": { "family": "Stockli", "given": "Daniel F." } }, { "id": "Dumitru-T-A", "name": { "family": "Dumitru", "given": "Trevor A." } }, { "id": "McWilliams-M-O", "name": { "family": "McWilliams", "given": "Michael O." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Cenozoic tectonic evolution of the White Mountains, California and Nevada", "ispublished": "pub", "full_text_status": "restricted", "keywords": "White Mountains; Basin and Range; Walker Lane belt; tectonics; thermochronology", "note": "\u00a9 2003 Geological Society of America. \nManuscript Received by the Society 25 April 2002;\nRevised Manuscript Received 11 December 2002;\nManuscript Accepted 17 December 2002.\nThis project was made possible through financial\nsupport by Stanford University McGee and Shell\nfund grants, a University of California White Mountains\nResearch Station fellowship (to Stockli), and\nNational Science Foundation grants EAR-9417937\nand EAR-9725371 (to E. Miller and Dumitru).\nStockli thanks L. Stockli, J. Hourigan, B. Surpless,\nand the staff of the White Mountains Research Station\nfor assistance in the field; L. Hedges and D.\nMiller for laboratory assistance, and F. Orr for aerial\nsupport. We also thank C. DePolo, W.G. Ernst, B.\nWernicke, M. House, and S. Klemperer for insightful\nand inspiring discussions and P. Fitzgerald, R.\nScott, and D. Foster for improving the final version\nof the manuscript.", "abstract": "The White Mountains represent the westernmost range of the central northern Basin and Range province. They are situated to the east of the unextended Sierra Nevada and represent a crustal block that is bounded along its western flank by the high-angle White Mountains fault zone. The fault zone accommodates up to \u223c8 km of total dip-slip displacement. Investigation of the structural and thermal history of the White Mountains indicates a two-stage Cenozoic tectonic evolution. Preextensional Miocene volcanic rocks preserved along the eastern side of the range unconformably overlie Mesozoic granitic basement and currently dip up to 25\u00b0 to the east, recording the total Cenozoic tilt of the crustal block. Apatite fission-track and (U-Th/He) thermochronological data indicate that the White Mountains underwent rapid exhumation and eastward tilting in the middle Miocene, starting at ca. 12 Ma. Geologic mapping (1:10,000), fault kinematic analysis, and dating of younger volcanic sequences show that following middle Miocene east-west extension, the White Mountains have been dominated by right-lateral transtensional deformation related to the Walker Lane belt. The eruption of late Miocene and Pliocene volcanic sequences in the eastern White Mountains postdates the majority of the uplift of the range, as evidenced by infilling of paleodrainages and the presence of east-directed flow fabrics. Fault kinematic indicators from the White Mountains fault zone are characterized by apparent overprinting of dip-slip fault-motion indicators by right-lateral slickenfibers and fault striations, demonstrating that the range-bounding fault system along the western side of the White Mountains was reactivated as a dextral strike-slip fault system. At the northern and southern ends of the range, Pliocene right-lateral transtension along this northwest\u2013southeast-trending fault systems resulted in the formation of northeast-trending pull-apart basins that truncate the mountain range and transfer strike-slip displacement eastward from the Owens Valley fault zone to the Fish Lake Valley fault zone. The inception of strike-slip faulting in Fish Lake Valley occurred at ca. 6 Ma as constrained by late Miocene volcanic units. Right-lateral faulting on the western side of the White Mountains occurred at ca. 3 Ma and is distinctly younger than the faulting in the Fish Lake Valley area, indicating a westward migration of transcurrent deformation through time.", "date": "2003-07", "date_type": "published", "publication": "Geological Society of America Bulletin", "volume": "115", "number": "7", "publisher": "Geological Society of America", "pagerange": "788-816", "id_number": "CaltechAUTHORS:20121114-160304585", "issn": "0016-7606", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121114-160304585", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Stanford University McGee and Shell Fund Grants" }, { "agency": "University of California White Mountains Research Station Fellowship" }, { "agency": "NSF", "grant_number": "EAR-9417937" }, { "agency": "NSF", "grant_number": "EAR-9725371" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/0016-7606(2003)115<0788:CTEOTW>2.0.CO;2", "resource_type": "article", "pub_year": "2003", "author_list": "Stockli, Daniel F.; Dumitru, Trevor A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/psx94-q1d51", "eprint_id": 35479, "eprint_status": "archive", "datestamp": "2023-08-23 23:37:36", "lastmod": "2023-10-20 16:23:50", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Min-K", "name": { "family": "Min", "given": "Kyoungwon" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Renne-P-R", "name": { "family": "Renne", "given": "Paul R." } }, { "id": "Marti-K", "name": { "family": "Marti", "given": "Kurt" } } ] }, "title": "Single grain (U-Th)/He ages from phosphates in Acapulco meteorite and implications for thermal history", "ispublished": "pub", "full_text_status": "public", "keywords": "(U\u2013Th)/He dating; Acapulco meteorite; apatite; whitlockite; thermal history", "note": "\u00a9 2003 Elsevier Science B.V. Received 9 September 2002; received in revised form 28 January 2003; accepted 12 February 2003. We thank John Donovan for assistance with\nEMP analyses, Lindsey Hedges for support in (U-Th)/He analyses, Yoosook Kim for mineral separations, Don DePaolo and Ken Ludwig for helpful discussion and suggestions. Constructive reviews of Grenville Turner and Edward Young\ngreatly improved the original manuscript. This work was supported by NSF Grant EAR-9814378 (P.R.R.).[BOYLE]\n\nSupplemental Material - mmc1.pdf
Supplemental Material - mmc2.pdf
Supplemental Material - mmc3.gif
", "abstract": "The cooling history of the Acapulco meteorite for >400\u00b0C is well established using various chronometers suggesting extremely fast cooling (>1000\u00b0C/Ma). In contrast, the thermal history for low temperatures (<400\u00b0C) is poorly understood because of large uncertainties in the chronometers applicable to this temperature range. To better constrain the cooling history for the low-temperature range, we applied (U\u2013Th)/He dating techniques to individual phosphate grains. One whitlockite and 11 apatite grains yielded (U\u2013Th)/He ages ranging from 1272\u00b122 (1\u03c3, analytical error only) Ma to 4584\u00b151 Ma, with tight clustering at \u223c4.55 Ga. The weighted mean of the five oldest ages (4538\u00b132 Ma, 1\u03c3 uncertainty including systematic error) is suggested to be the minimum age representing primary cooling of the Acapulco body passing through \u223c120\u00b0C. Although it is impossible to precisely quantify the effects of energetic \u03b1 particle ejection from the outermost \u223c20 \u03bcm of the phosphates, petrographic evidence suggests that most dated samples are fragments likely derived from the interior of larger grains, thus greatly reducing this source of error. Indeed the five oldest samples cannot have suffered substantial ejection since the uncorrected ages are identical with the crystallization age of the Acapulco meteorite. The new (U\u2013Th)/He data suggest rapid cooling of Acapulco down to \u223c120\u00b0C. This evidence suggests that the younger ^(40)Ar/^(39)Ar age (4507\u00b19 (1\u03c3) Ma) obtained from Acapulco plagioclase, which should reflect cooling through \u223c300\u00b0C, is spuriously young due to systematic errors (i.e., decay constants and/or standard data) in the ^(40)Ar/^(39)Ar method, as suggested by comparison between high-precision ^(40)Ar/^(39)Ar and U/Pb ages for terrestrial volcanic rocks. The scattered He age distribution <4.0 Ga implies very heterogeneous thermal disturbances after the primary cooling of the body.", "date": "2003-04-30", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "209", "number": "3-4", "publisher": "Elsevier", "pagerange": "323-336", "id_number": "CaltechAUTHORS:20121115-095120262", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121115-095120262", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9814378" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(03)00080-3", "primary_object": { "basename": "medium.png", "url": "https://authors.library.caltech.edu/records/psx94-q1d51/files/medium.png" }, "related_objects": [ { "basename": "mmc1.pdf", "url": "https://authors.library.caltech.edu/records/psx94-q1d51/files/mmc1.pdf" }, { "basename": "mmc2.pdf", "url": "https://authors.library.caltech.edu/records/psx94-q1d51/files/mmc2.pdf" }, { "basename": "mmc3.gif", "url": "https://authors.library.caltech.edu/records/psx94-q1d51/files/mmc3.gif" }, { "basename": "small.png", "url": "https://authors.library.caltech.edu/records/psx94-q1d51/files/small.png" } ], "resource_type": "article", "pub_year": "2003", "author_list": "Min, Kyoungwon; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/bf4cg-per03", "eprint_id": 35478, "eprint_status": "archive", "datestamp": "2023-08-23 23:37:25", "lastmod": "2023-10-20 16:23:46", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Eltgroth-S-F", "name": { "family": "Eltgroth", "given": "S. F." } } ] }, "title": "An alternative age model for the Paleocene-Eocene thermal\n maximum using extraterrestrial ^3He", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2003 Elsevier Science B.V. Received 27 September 2002; received in revised form 5 January 2003; accepted 8 January 2003. We thank Tim Bralower for guidance, encouragement\nand helpful comments on the manuscript, Debbie Thomas for preparation of samples from Site 690, and constructive reviews by Jim Zachos and Franco Marcantonio. This work\nwas supported by NSF EAR-9909448 and by a Fellowship from the David and Lucille Packard Foundation to K.A.F.[BARD]\n\nSupplemental Material - mmc1.xls
", "abstract": "A continuous age model for the brief climate excursion at the Paleocene\u2013Eocene boundary has been constructed by assuming a constant flux of extraterrestrial ^3He (^3He_(ET)) to the seafloor. ^3He_(ET) measurements from ODP Site 690 provide quantitative evidence for the rapid onset (", "date": "2003-03-30", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "208", "number": "2-4", "publisher": "Elsevier", "pagerange": "135-148", "id_number": "CaltechAUTHORS:20121115-093445626", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121115-093445626", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9909448" }, { "agency": "David and Lucile Packard Foundation Fellowship" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(03)00017-7", "primary_object": { "basename": "mmc1.xls", "url": "https://authors.library.caltech.edu/records/bf4cg-per03/files/mmc1.xls" }, "resource_type": "article", "pub_year": "2003", "author_list": "Farley, K. A. and Eltgroth, S. F." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/e6vrb-awp87", "eprint_id": 38040, "eprint_status": "archive", "datestamp": "2023-08-23 23:40:34", "lastmod": "2023-10-23 19:42:51", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Armstrong-P-A", "name": { "family": "Armstrong", "given": "Philip A." } }, { "id": "Ehlers-T-A", "name": { "family": "Ehlers", "given": "Todd A." } }, { "id": "Chapman-D-S", "name": { "family": "Chapman", "given": "David S." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Kamp-P-J-J", "name": { "family": "Kamp", "given": "Peter J. J." } } ] }, "title": "Exhumation of the central Wasatch Mountains, Utah: 1. Patterns and timing of exhumation deduced from low-temperature thermochronology data", "ispublished": "pub", "full_text_status": "public", "keywords": "Wasatch Mountains, exhumation, fission track, helium dating", "note": "\u00a9 2003 American Geophysical Union. Received 11 December 2001; revised 27 September 2002; accepted 1 October 2002; published 29 March 2003. We thank W. Parry, R. Bruhn, B. Kowallis, and K. Constenius for supplying sample splits for this study and E. Reinert, L. Cannon, M. Perkins, and L. Hedges for help with sample collection and preparation. Discussions of Wasatch geology with J. Bartley, R. Bruhn, B.\nKowallis, and K. Constenius are greatly appreciated. R. Donelick supplied the Cf-252 irradiations. This paper greatly benefited from reviews by R. Ketcham, S. Thompson, and Associate Editor J. Braun. Research was funded by NSF grant EAR-9805073 to Armstrong and Chapman.\n\nPublished - 2001JB001708.pdf
", "abstract": "The Wasatch Mountains are often cited as an example of normal fault growth and footwall flexure. They represent a tilted footwall at the edge of the Basin and Range extensional province, a major rift basin. Thus understanding the detailed spatial and elevation changes in coupled thermochronometer data, and how these changes can be interpreted, may aid in the analysis of thermochronometer data from other extensional regions around the world. We present a dense data set from the Cottonwood Intrusive Belt (CIB) of the Wasatch that includes apatite fission track (AFT), zircon fission track (ZFT), and apatite (U-Th)/He ages. ZFT, AFT, and apatite (U-Th)/He ages are 10, 5, and 3 Ma, respectively, adjacent to the Wasatch fault. AFT and (U-Th)/He ages increase slightly with distance east of the fault until about 15\u201320 km, where a more abrupt increase in these ages occurs at or near the Silver Fork-Superior fault zone. ZFT and AFT ages are concordant with 31\u201338 Ma pluton emplacement ages on the eastern side of range. Modeling of the data leads to the following interpretation: (1) Early cooling and \u223c3\u20134 km of exhumation for the middle and eastern parts of the range occurred in the late Oligocene-middle Miocene. (2) Beginning at 10\u201312 Ma, the locus of exhumation shifted westward toward the present range front, where the rocks cooled from >200\u00b0C in the last 10\u201312 Myr. Our data and interpretations are consistent with a model in which the locus of faulting and exhumation shifted opposite the direction of tilt, similar to that predicted by rolling-hinge extensional models. However, this westward shift and rapid Miocene to recent exhumation may be a local effect superimposed on lower fault displacement and exhumation rates elsewhere along the Wasatch.", "date": "2003-03-29", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "108", "number": "B3", "publisher": "American Geophysical Union", "pagerange": "Art. No. 2172", "id_number": "CaltechAUTHORS:20130419-114812746", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130419-114812746", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9805073" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2001JB001708", "primary_object": { "basename": "2001JB001708.pdf", "url": "https://authors.library.caltech.edu/records/e6vrb-awp87/files/2001JB001708.pdf" }, "resource_type": "article", "pub_year": "2003", "author_list": "Armstrong, Philip A.; Ehlers, Todd A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/62330-tjy46", "eprint_id": 35476, "eprint_status": "archive", "datestamp": "2023-08-23 23:37:17", "lastmod": "2023-10-20 16:23:32", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tagami-T", "name": { "family": "Tagami", "given": "Takahiro" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Stockli-D-F", "name": { "family": "Stockli", "given": "Daniel F." } } ] }, "title": "(U-Th)/He geochronology of single zircon grains of known Tertiary eruption age", "ispublished": "pub", "full_text_status": "restricted", "keywords": "zircon; helium; geochronology; standard; laser heating", "note": "\u00a9 2003 Elsevier Science B.V. Received 10 July 2002; received in revised form 15 October 2002; accepted 11 December 2002. We thank Martha House and Lindsey Hedges\nfor their help and suggestions. We also thank Chuck Naeser and Tony Hurford for supplying the standard zircons. T. T. thanks Kyoto University Foundation for leave to Caltech. This work was supported in part by the National Science\nFoundation.[BW]", "abstract": "We performed a systematic study of (U\u2013Th)/He ages of volcanic zircons of known eruption age to establish a reliable protocol for zircon He dating and to validate the resulting ages. Using laser He extraction and dissolution by lithium borate flux melting we analyzed many aliquots of single zircon grains separated from four rapidly cooled rocks: Fish Canyon Tuff (accepted age 27.8\u00b10.7 Ma), Buluk Tuff (16.3\u00b10.2 Ma), Tardree Rhyolite (58.4\u00b10.7 Ma) and Utaosa Rhyolite (2.52\u00b10.02 Ma). He ages of Fish Canyon Tuff, Buluk Tuff and Utaosa Rhyolite zircons are in good agreement with their reference ages: mean \u03b1 emission-corrected ages were 28.6\u00b11.4 (1\u03c3), 16.1\u00b10.8 and 2.61\u00b10.18 Ma, respectively. However, the zircon He ages of Tardree Rhyolite are irreproducible and consistently too old, with a mean He age of 78.8\u00b17.0 Ma. Spontaneous fission track densities of Tardree Rhyolite zircons indicate that about 80% of these zircons are strongly zoned in U, with high track density (i.e., high U content) in the core and low density on the rim. This causes an overestimation of the \u03b1 ejection correction that likely explains the erratic and excessively high He ages from these zircons. Assessment of the degree and style of U zonation within a zircon population is thus prudent before application of the (U\u2013Th)/He method. Step-heating experiments indicate that for most zircons He extraction is >99% complete after \u223c1 h at 1300\u00b0C. However, for as yet unknown reasons occasional grains seem to retain substantial amounts of He under these conditions.", "date": "2003-02-28", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "207", "number": "1-4", "publisher": "Elsevier", "pagerange": "57-67", "id_number": "CaltechAUTHORS:20121115-092559670", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121115-092559670", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(02)01144-5", "resource_type": "article", "pub_year": "2003", "author_list": "Tagami, Takahiro; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/4cpx4-3qv70", "eprint_id": 35475, "eprint_status": "archive", "datestamp": "2023-08-23 23:37:11", "lastmod": "2023-10-20 16:23:22", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ehlers-T-A", "name": { "family": "Ehlers", "given": "Todd A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Apatite (U-Th)/He thermochronometry: methods and\n applications to problems in tectonic and surface processes", "ispublished": "pub", "full_text_status": "restricted", "keywords": "apatite; (U\u2013Th)/He; thermochronometry; surface processes; tectonics; numerical modeling", "note": "\u00a9 2002 Elsevier Science B.V. Received 11 July 2002; received in revised form 1 October 2002; accepted 5 November 2002. This research was funded by the National Science Foundation. Margie Rusmore and Glenn Woodsworth are thanked for thoughtful discussions about Coast Mountains, BC geology. Digital elevation models used in Figures 7 and 8 were provided through collaboration with G. Woodsworth\nand the Canadian Geologic Survey. We acknowledge Simon P. Kelley and Urs Schaltegger for constructive reviews.[AH]", "abstract": "In the last decade apatite (U\u2013Th)/He thermochronometry has emerged as an important tool for quantifying the cooling history of rocks as they pass through the upper 1\u20133 km of the crust. The low closure temperature of this technique (\u223c70\u00b0C) has gained the interest of geomorphologists and tectonocists because it is applicable to interdisciplinary studies in landform evolution, structural geology, and geodynamics. We discuss current analytical techniques, the temperature calibration of the method, and sample quality considerations. Results from 1D, 2D and 3D thermo-kinematic numerical models are used to illustrate applications of He thermochronometry to problems in tectonics and landform evolution.", "date": "2003-01-30", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "206", "number": "1-2", "publisher": "Elsevier", "pagerange": "1-14", "id_number": "CaltechAUTHORS:20121115-091441978", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121115-091441978", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(02)01069-5", "resource_type": "article", "pub_year": "2003", "author_list": "Ehlers, Todd A. and Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/xwgvy-0kv33", "eprint_id": 1122, "eprint_status": "archive", "datestamp": "2023-08-23 23:24:50", "lastmod": "2023-10-13 22:37:47", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mukhopadhyay-S", "name": { "family": "Mukhopadhyay", "given": "S." } }, { "id": "Lassiter-J-C", "name": { "family": "Lassiter", "given": "J. C." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Bogue-S-W", "name": { "family": "Bogue", "given": "S. W." } } ] }, "title": "Geochemistry of Kauai shield-stage lavas: Implications for the chemical evolution of the Hawaiian plume", "ispublished": "pub", "full_text_status": "public", "keywords": "Helium; mantle plumes; Hawaii; isotope ratios; mixing; 1010 Geochemistry: Chemical evolution; 1025 Geochemistry: Composition of the mantle; 1040 Geochemistry: Isotopic composition/chemistry; 8121 Tectonophysics: Dynamics, convection currents and mantle plumes", "note": "Copyright 2003 by the American Geophysical Union. \n\nReceived: 7 March 2002; Revised: 14 August 2002; Accepted: 30 August 2002; Published: 24 January 2003. \n\nWe thank John Eiler, Mike Baker, Pete Burnard, and Pete Reiners for stimulating discussions on Hawaiian magmatism. We thank John Eiler and Pete Burnard for making valuable suggestions on an earlier version of this manuscript. Don DePaolo, Mike Garcia, and Mark Kurz are thanked for their thoughtful reviews. This work was funded by the David and Lucille Packard fellowship to KAF, the NSF grant EAR-9725351 to John Lassiter, and the Max-Plank Institut.", "abstract": "We measured He, Sr, Nd, Pb, and Os isotope ratios and major and trace element concentrations in stratigraphically and paleomagnetically controlled shield-stage lavas from Kauai, Hawaii. The range of 3He/4He ratios (17\u201328 RA) from Kauai is similar to that reported from Loihi and thus challenges the prevailing notion that high 3He/4He ratios are restricted to the preshield stage of Hawaiian magmatism. 3He/4He ratios vary erratically with stratigraphic position, and chronostratigraphic control from paleomagnetic data indicates very rapid changes in the 3He/4He ratios (up to 8 RA in ~102 years). These variations in helium isotopic ratios are correlated with variations in radiogenic isotope ratios, suggesting rapid changes in melt composition supplying the magma reservoir. A three-component mixing model, previously proposed for Hawaiian shield lavas, does not adequately explain the isotopic data in Kauai shield lavas. The addition of a depleted-mantle (DM) component with the isotopic characteristics similar to posterosional basalts explains the isotopic variability in Kauai shield lavas. The DM component is most apparent in lavas from the Kauai shield and is present in varying proportion in other Hawaiian shield volcanoes. Shield lavas from Kauai sample a high 3He/4He end-member (Loihi component), but while lavas from western Kauai have a larger contribution from the Kea component (high 206Pb/204Pb, anomalously low 207Pb/204Pb relative to 206Pb/204Pb), lavas from eastern Kauai have a larger proportion of an enriched (Koolau) component. The systematic isotopic differences between eastern and western Kauai reflect a gradual migration of the locus of volcanism from west to east, or alternatively east and west Kauai are two distinct shield volcanoes. In the latter case, the two shield volcanoes have maintained distinct magma supply sources and plumbing systems. Our new geochemical data from Kauai are consistent with the existence of a single high 3He/4He reservoir in the Hawaiian plume and suggest that the proportion of the different mantle components in the plume have changed significantly in the past 5 Myr. The long-term evolution of the Hawaiian plume and the temporal variability recorded in Kauai lavas require more complex geochemical heterogeneities than suggested by radially zoned plume models. These complexities may arise from heterogeneities in the thermal boundary layer and through variable entrainment of ambient mantle by the upwelling plume.", "date": "2003-01-24", "date_type": "published", "publication": "Geochemistry, Geophysics, Geosystems", "volume": "4", "number": "1", "publisher": "American Geophysical Union", "pagerange": "2002GC000342", "id_number": "CaltechAUTHORS:MUKggg03", "issn": "1525-2027", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:MUKggg03", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2002GC000342", "primary_object": { "basename": "MUKggg03.pdf", "url": "https://authors.library.caltech.edu/records/xwgvy-0kv33/files/MUKggg03.pdf" }, "resource_type": "article", "pub_year": "2003", "author_list": "Mukhopadhyay, S.; Lassiter, J. C.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/x1a3r-hge60", "eprint_id": 35473, "eprint_status": "archive", "datestamp": "2023-08-23 23:37:04", "lastmod": "2023-10-20 16:23:10", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Burnard-P-G", "name": { "family": "Burnard", "given": "P. G." } }, { "id": "Graham-D-W", "name": { "family": "Graham", "given": "D. W." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Mechanisms of magmatic gas loss along the Southeast Indian\n Ridge and the Amsterdam -St. Paul Plateau", "ispublished": "pub", "full_text_status": "public", "keywords": "Southeast Indian Ridge; degassing; magmas; noble gases; fractional crystallization", "note": "\u00a9 2002 Elsevier Science B.V. Received 20 November 2001; received in revised form 10 April 2002; accepted 12 July 2002. This work was supported by the Marine Geology and Geophysics program of the NSF. Discussions with Bernard Marty were valuable in formulating the ideas behind this study, and reviews by Bernard Marty and Chris Ballentine\nconsiderably improved the final manuscript. [BOYLE]\n\nSupplemental Material - mmc1.doc
Supplemental Material - mmc2.doc
", "abstract": "New analyses of He, Ne, Ar and CO_2 trapped in basaltic glasses from the Southeast Indian Ridge (Amsterdam\u2013St. Paul (ASP) region) show that ridge magmas degas by a Rayleigh distillation process. As a result, the absolute and relative noble gas abundances are highly fractionated with ^4He/^(40)Ar^* ratios as high as 620 compared to a production ratio of \u223c3 (where ^(40)Ar^* is ^(40)Ar corrected for atmospheric contamination). There is a good correlation between ^4He/^(40)Ar^* and the MgO content of the basalt, suggesting that the amount of gas lost from a particular magma is related to the degree of crystallization. Fractional crystallization forces oversaturation of CO_2 because CO_2 is an incompatible element. Therefore, crystallization will increase the fraction of gas lost from the magma. The He\u2013Ar\u2013CO_2\u2013MgO\u2013TiO_2 compositions of the ASP basalts are modeled as a combined fractional crystallization\u2013fractional degassing process using experimentally determined noble gas and CO_2 solubilities and partition coefficients at reasonable magmatic pressures (2\u20134 kbar). The combined fractional crystallization\u2013degassing model reproduces the basalt compositions well, although it is not possible to rule out depth of eruption as a potential additional control on the extent of degassing. The extent of degassing determines the relative noble gas abundances (^4He/^(40)Ar^*) and the ^(40)Ar^*/CO_2 ratio but it cannot account for large (>factor 50) variations in He/CO_2, due to the similar solubilities of He and CO_2 in basaltic magmas. Instead, variations in CO_2/^3He (\u2261C/^3He) trapped in the vesicles must reflect similar variations in the primary magma. The controls on C/^3He in mid-ocean ridge basalts (MORBs) are not known. There are no obvious correlated variations between C/^3He and tracers of mantle heterogeneity (^3He/^4He, K/Ti etc.), implying that the variations in C/^3He are not likely to be a feature of the mantle source to these basalts. Mixing between MORB-like sources and more enriched, high ^3He/^4He sources occurs on and near the ASP plateau, resulting in variable ^3He/^4He and K/Ti compositions (and many other tracers). Using ^4He/^(40)Ar^* to track degassing, we demonstrate that mixing systematics involving He isotopes are determined in large part by the extent of degassing. Relatively undegassed lavas (with low ^4He/^(40)Ar^*) are characterized by steep ^3He/^4He\u2013K/Ti mixing curves, with high He/Ti ratios in the enriched magma (relative to He/Ti in the MORB magma). Degassed samples (high ^4He/^(40)Ar^*) on the other hand have roughly equal He/Ti ratios in both end-members, resulting in linear mixing trajectories involving He isotopes. Some degassing of ASP magmas must occur at depth, prior to magma mixing. As a result of degassing prior to mixing, mixing systematics of oceanic basalts that involve noble gas\u2013lithophile pairs (e.g. ^3He/^4He vs. ^(87)Sr/^(86)Sr or ^(40)Ar/^(36)Ar vs. ^(206)Pb/^(204)Pb) are unlikely to reflect the noble gas composition of the mantle source to the basalts. Instead, the mixing curve will reflect the extent of gas loss from the magmas, which is in turn buffered by the pressure of combined crystallization\u2013degassing and the initial CO_2 content.", "date": "2002-10-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "203", "number": "1", "publisher": "Elsevier", "pagerange": "131-148", "id_number": "CaltechAUTHORS:20121115-084957583", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121115-084957583", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF Marine Geology and Geophysics program" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(02)00828-2", "primary_object": { "basename": "mmc2.doc", "url": "https://authors.library.caltech.edu/records/x1a3r-hge60/files/mmc2.doc" }, "related_objects": [ { "basename": "mmc1.doc", "url": "https://authors.library.caltech.edu/records/x1a3r-hge60/files/mmc1.doc" } ], "resource_type": "article", "pub_year": "2002", "author_list": "Burnard, P. G.; Graham, D. W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/0r090-gvf91", "eprint_id": 57299, "eprint_status": "archive", "datestamp": "2023-08-22 01:28:46", "lastmod": "2023-10-23 17:14:58", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Shuster-D-L", "name": { "family": "Shuster", "given": "D. L." } }, { "id": "Burnett-D-S", "name": { "family": "Burnett", "given": "D. S." }, "orcid": "0000-0001-9521-8675" }, { "id": "Sisterson-J-M", "name": { "family": "Sisterson", "given": "J." } } ] }, "title": "Using proton-induced ^3He to study He diffusion kinetics and rock thermal histories", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2002 Published by Elsevier Ltd.", "abstract": "We have investigated He release kinetics by step-heating\nof minerals in which we introduced artificial ^3He with a beam\nof ~150 MeV protons in a particle accelerator used primarily\nfor cancer therapy. This process mimics cosmic-ray spallation,\nand produces He with a ^3He/^4He ratio of about unity. The\ninduced helium is homogeneously distributed within the target\ncrystals, and because it is emitted with few MeV energies, the\n^3He should reside in sites indistinguishable from those of\nradiogenic ^4He.", "date": "2002-08-15", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "66", "number": "15A", "publisher": "Elsevier", "pagerange": "A224", "id_number": "CaltechAUTHORS:20150506-155302502", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150506-155302502", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0016-7037(02)01009-8", "resource_type": "article", "pub_year": "2002", "author_list": "Farley, K. A.; Shuster, D. L.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/tx560-2m225", "eprint_id": 37948, "eprint_status": "archive", "datestamp": "2023-08-22 01:27:10", "lastmod": "2023-10-23 19:34:57", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Stockli-D-F", "name": { "family": "Stockli", "given": "Daniel F." } }, { "id": "Surpless-B-E", "name": { "family": "Surpless", "given": "Benjamin E." } }, { "id": "Dumitru-T-A", "name": { "family": "Dumitru", "given": "Trevor A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Thermochronological constraints on the timing and magnitude of Miocene and Pliocene extension in the central Wassuk Range, western Nevada", "ispublished": "pub", "full_text_status": "public", "keywords": "Basin and Range; Walker Lane Belt; Wassuk Range; extension; thermochronology", "note": "\u00a9 2002 by the American Geophysical Union.\n\nReceived 23 April 2001; revised 5 February 2002; accepted 27 February 2002; published 8 August 2002.\n\nThis project was supported by NSF grants\nEAR-9417939 and EAR-9725371 (to E. L. Miller and T. A. Dumitru),\nCaltech postdoctoral fellowship to D. Stockli, and a Packard fellowship to\nK. Farley. We would like to thank E. Miller, M. McWilliams, J. Dilles, J.\nOldow, and S. Klemperer for stimulating discussions and helpful insights,\nand B. Wernicke and P. Armstrong for improving the final version of the\nmanuscript.\n\nPublished - 2001TC001295.pdf
", "abstract": "Apatite fission track and (U-Th)/He thermochronological data provide new constraints on the timing of faulting and exhumation of the Wassuk Range, western Nevada, where east dipping normal faults have accommodated large-magnitude ENE-WSW oriented extension. Extensional deformation has resulted in the exhumation of structurally coherent fault blocks that expose sections of preextensional mostly granitic upper crust in the Grey Hills and central Wassuk Range. These fault blocks display westward tilts of \u223c60\u00b0 and expose preextensional paleodepths of up to \u223c8.5 km, based on the structural reconstruction of tilted preextensional Tertiary andesite flows that unconformably overlie Mesozoic basement rocks. Apatite fission track and (U-Th)/He thermochronological data from the fault blocks constrain the onset of rapid footwall exhumation at \u223c15 Ma. Fission track modeling results indicate rapid fault block exhumation occurred between \u223c15 and 12 Ma, which is in agreement with Miocene volcanic rocks that bracket the tilting history. In addition, fission track and (U-Th)/He data suggest reduced rates of cooling following major extension, as well as renewed cooling related to active, high-angle faulting along the present-day range front starting at \u223c4 Ma. Thermochronological data from structurally restored fault blocks indicate a preextensional Miocene geothermal gradient of 27\u00b0 \u00b1 5\u00b0C/km. The thermochronological constraints on the timing of extensional faulting and the eruptive history in the Wassuk Range imply a model for extension where crustal heating and volcanism precede the onset of rapid large magnitude extension, and where synextensional magmatism is suppressed during the highest rates of extension.", "date": "2002-08", "date_type": "published", "publication": "Tectonics", "volume": "21", "number": "4", "publisher": "American Geophysical Union", "pagerange": "Art. No. 1028", "id_number": "CaltechAUTHORS:20130415-142346938", "issn": "0278-7407", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130415-142346938", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9417939" }, { "agency": "NSF", "grant_number": "EAR-9725371" }, { "agency": "Caltech Postdoctoral Fellowship" }, { "agency": "Packard Fellowship" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2001TC001295", "primary_object": { "basename": "2001TC001295.pdf", "url": "https://authors.library.caltech.edu/records/tx560-2m225/files/2001TC001295.pdf" }, "resource_type": "article", "pub_year": "2002", "author_list": "Stockli, Daniel F.; Surpless, Benjamin E.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/8w09p-bjh02", "eprint_id": 35470, "eprint_status": "archive", "datestamp": "2023-08-22 01:26:27", "lastmod": "2023-10-20 16:22:54", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Kohn-B-P", "name": { "family": "Kohn", "given": "B. P." } }, { "id": "Pillans-B", "name": { "family": "Pillans", "given": "B." } } ] }, "title": "The effects of secular disequilibrium on (U-Th)/He\n systematics and dating of Quaternary volcanic zircon and\n apatite", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Th/U; zircon; apatite; Quaternary; volcanic rocks; uranium disequilibrium", "note": "\u00a9 2002 Published by Elsevier Science B.V. Received 19 December 2001; received in revised form 25 March 2002; accepted 5 April 2002. This study was supported by the Australian Research Council and a fellowship to K.A.F.\nfrom the David and Lucille Packard Foundation. K.A.F. thanks A. Gleadow and the University of Melbourne for hosting a sabbatical leave. Mary Reid, Ian Fletcher, Tim Elliot and Fin Stuart provided helpful comments on the manuscript. [BARD]", "abstract": "The (U\u2013Th)/He dating method applied to U-rich phases such as zircon and apatite has sufficient sensitivity and precision to be of potential use for dating relatively recent geologic events such as volcanic eruptions. However, in phases with crystallization ages less than \u223c1 Ma, chemical fractionation within the ^(238)U decay series may modify the He ingrowth rate, causing He ages computed from the secular equilibrium age equation to be incorrect. The resulting systematic error depends on the [^(230)Th/^(238)U] activity ratio of the dated phase when it is erupted, and on the eruption age. Zircons, which exclude Th relative to U, will likely have secular equilibrium He 'ages' that underestimate the eruption age by up to a few tens of %, decreasing with increasing eruption age. Apatites tend to accommodate U and Th with little fractionation, so apatite secular equilibrium He ages will be nearly concordant with eruption age. If minerals are erupted immediately after crystallization, the disequilibrium effect can be reasonably accounted for based on Th/U systematics. However, crystals are likely to reside for unknown but potentially long periods in a magma chamber, such that the degree of secular disequilibrium will be reduced prior to the onset of He accumulation. (U\u2013Th)/He analyses of co-genetic phases that fractionate the U/Th ratio differently, like apatite and zircon, can be used to better constrain eruption age, as well as to provide insights into magma chamber residence time. We illustrate this approach with (U\u2013Th)/He analyses of zircons and apatites of the Pleistocene-age Rangitawa Tephra, New Zealand.", "date": "2002-07-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "201", "number": "1", "publisher": "Elsevier", "pagerange": "117-125", "id_number": "CaltechAUTHORS:20121115-080342768", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121115-080342768", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Australian Research Council" }, { "agency": "David and Lucile Packard Foundation Fellowship" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(02)00659-3", "resource_type": "article", "pub_year": "2002", "author_list": "Farley, K. A.; Kohn, B. P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/21vjm-vrk68", "eprint_id": 35597, "eprint_status": "archive", "datestamp": "2023-08-22 01:24:18", "lastmod": "2023-10-20 19:12:12", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "House-M-A", "name": { "family": "House", "given": "M. A." } }, { "id": "Kohn-B-P", "name": { "family": "Kohn", "given": "B. P." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Raza-A", "name": { "family": "Raza", "given": "A." } } ] }, "title": "Evaluating thermal history models for the Otway Basin,\n southeastern Australia, using (U-Th)/He and fission-track\n data from borehole apatites", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Helium; Fission track; Age; Apatite; Thermal history; Otway Basin", "note": "\u00a9 2002 Elsevier Science B.V. Received 1 August 2000; accepted 27 July 2001. Acknowledgment is made to the Donors of the Petroleum Research Fund, administered by the\nAmerican Chemical Society, the Australian Research\nCouncil and NSF for support of this research. Neutron\nirradiation costs were covered by the Australian\nInstitute of Nuclear Science and Engineering. Lindsey\nHedges of the Noble Gas Laboratory at Caltech\nprovided analytical assistance. Kathy Hill, Ken\nWilson and Bob Harms of the Petroleum Division\nof the Victorian Department of Natural Resources and\nEnvironment greatly facilitated the examination of the\nOtway Basin well reports studied and the collection of\ncore samples. Kevin Hill and Chuck Naeser provided\nconstructive criticism of an earlier draft of this work.", "abstract": "New apatite helium and fission-track data from the Otway Basin are consistent with previously published borehole ages, confirming earlier suggestions that existing thermal models for basin evolution should be reevaluated. Analysis of the relationship between helium ages and grain size in newly analyzed samples, as well as in samples previously reported, reveals that grain size variations may contribute to the previously reported scatter in helium ages among aliquots of the same sample. In addition, systematic variations in apatite grain size with borehole depth or temperature may also have a significant effect on the interpretation of borehole helium age data. Incorporation of the observed grain size variations in Otway borehole apatites into forward models based on published thermal histories, principally based on vitrinite reflectance and fission-track data, suggests that existing models for the eastern Otway Basin are broadly consistent with the helium data. In contrast, thermal histories for western basin boreholes, now thought to be at maximum temperatures, predict helium ages that are generally older than the observed ages, implying that basin temperatures were hotter than indicated by the models. This discrepancy is consistent with a Cenozoic heating event in parts of the western Otway Basin similar to that documented for the eastern basin. The relatively wide spread of apparent apatite fission-track (AFT) ages and compositions compared to the restricted age range of helium measurements on coexisting grains, although not conclusive, supports previous suggestions that composition does not appear to affect the sensitivity of the He closure temperature in apatite.", "date": "2002-05-06", "date_type": "published", "publication": "Tectonophysics", "volume": "349", "number": "1-4", "publisher": "Elsevier", "pagerange": "277-295", "id_number": "CaltechAUTHORS:20121121-091554048", "issn": "0040-1951", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121121-091554048", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "American Chemical Society Petroleum Research Fund" }, { "agency": "Australian Research Council" }, { "agency": "NSF" }, { "agency": "Australian Institute of Nuclear Science and Engineering (AINSE)" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0040-1951(02)00057-4", "resource_type": "article", "pub_year": "2002", "author_list": "House, M. A.; Kohn, B. P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/f65jv-a2v46", "eprint_id": 35598, "eprint_status": "archive", "datestamp": "2023-08-22 01:24:27", "lastmod": "2023-10-20 19:12:18", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Reiners-P-W", "name": { "family": "Reiners", "given": "Peter W." }, "orcid": "0000-0001-7240-2373" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Hickes-H-J", "name": { "family": "Hickes", "given": "Hunter J." } } ] }, "title": "He diffusion and (U\u2013Th)/He thermochronometry of zircon:\n initial results from Fish Canyon Tuff and Gold Butte", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Thermochronology; (U\u2013Th)/He; Geochronology; Zircon; Helium", "note": "\u00a9 2002 Elsevier Science B.V. Received 20 June 2000; accepted 27 July 2001. Thanks to Barry Kohn for the FCT samples, Matt\nHeizler for the Chain of Ponds sample, Mark Garcia\nfor mineral separations, Lindsey Hedges for help with\nzircon dissolutions at Caltech, Charles Knaack for\ntechnical and analytical help at WSU, Scotty\nCornelius for microprobe help, and Rob Brady for\nhelp in the field at and with geologic interpretation of Gold Butte. We appreciate constructive and thoughtprovoking\nreviews from Fin Stuart and Mark\nHarrison. This work was supported in part by NSF\nEAR 0073576 to PWR and NSF grants to KAF.", "abstract": "To evaluate the potential of (U\u2013Th)/He geochronometry and thermochronometry of zircon, we measured He diffusion characteristics in zircons from a range of quickly and slowly cooled samples, (U\u2013Th)/He ages of zircons from the quickly cooled Fish Canyon Tuff, and age-paleodepth relationships for samples from 15 to 18 km thick crustal section of the Gold Butte block, Nevada. (U\u2013Th)/He ages of zircons from the Fish Canyon Tuff are consistent with accepted ages for this tuff, indicating that the method can provide accurate ages for quickly cooled samples. Temperature-dependent He release from zircon is not consistent with thermally activated volume diffusion from a single domain. Instead, in most samples apparent He diffusivity decreases and activation energy (E_a) increases as cycled step-heating experiments proceed. This pattern may indicate a range of diffusion domains with distinct sizes and possibly other characteristics. Alternatively, it may be the result of ongoing annealing of radiation damage during the experiment. From these data, we tentatively suggest that the minimum E_a for He diffusion in zircon is about 44 kcal/mol, and the minimum closure temperature (T_c, for a cooling rate of 10 \u00b0C/myr) is about 190 \u00b0C. Age\u2013paleodepth relationships from the Gold Butte block suggest that the base of the zircon He partial retention zone is at pre-exhumation depths of about 9.5\u201311 km. Together with constraints from other thermochronometers and a geothermal gradient derived from them in this location, the age\u2013depth profile suggests a He T_c of about 200 \u00b0C for zircon, in reasonable agreement with our interpretation of the laboratory measurements. A major unresolved question is how and when radiation damage effects become significant for He loss from this mineral.", "date": "2002-05-06", "date_type": "published", "publication": "Tectonophysics", "volume": "349", "number": "1-4", "publisher": "Elsevier", "pagerange": "297-308", "id_number": "CaltechAUTHORS:20121121-093240494", "issn": "0040-1951", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121121-093240494", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR 0073576" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0040-1951(02)00058-6", "resource_type": "article", "pub_year": "2002", "author_list": "Reiners, Peter W.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/sbvw8-v9r46", "eprint_id": 37501, "eprint_status": "archive", "datestamp": "2023-08-22 01:20:02", "lastmod": "2023-10-23 17:42:02", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kirby-Eric", "name": { "family": "Kirby", "given": "Eric" }, "orcid": "0000-0002-5701-8688" }, { "id": "Reiners-P-W", "name": { "family": "Reiners", "given": "Peter W." }, "orcid": "0000-0001-7240-2373" }, { "id": "Krol-M-A", "name": { "family": "Krol", "given": "Michael A." } }, { "id": "Whipple-K-X", "name": { "family": "Whipple", "given": "Kelin X." }, "orcid": "0000-0002-8430-6925" }, { "id": "Hodges-K-V", "name": { "family": "Hodges", "given": "Kip V." }, "orcid": "0000-0003-2805-8899" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Tang-Wenqing", "name": { "family": "Tang", "given": "Wenqing" } }, { "id": "Chen-Zhiliang", "name": { "family": "Chen", "given": "Zhiliang" } } ] }, "title": "Late Cenozoic evolution of the eastern margin of the Tibetan Plateau: Inferences from ^(40)Ar/^(39)Ar and (U-Th)/He thermochronology", "ispublished": "pub", "full_text_status": "public", "keywords": "Tibetan Plateau; thermochronology; denudation; relief", "note": "\u00a9 2002 American Geophysical Union.\n\nReceived 29 June 2000; revised 20 July 2001; accepted 20 August 2001; published 1 January 2002.\n\nOur work in eastern Tibet has been supported by the NSF Continental Dynamics program (EAR-9614970 and EAR-9725723). Reviews by Mihai Ducea, Dave Foster, Brad Hacker, and Brian Wernicke significantly improved the manuscript. We wish to acknowledge preliminary (U-Th)/He and fission track analyses by Martha House (Caltech) and Shari Kelly (NMT) which, although not included here, were instrumental in helping us design a sampling strategy. We also thank Clark Burchfiel, Marin Clark, and Wiki Royden for lively discussions.\n\nPublished - 2000TC001246.pdf
", "abstract": "High topography in central Asia is perhaps the most fundamental expression of the Cenozoic Indo-Asian collision, yet an understanding of the timing and rates of development of the Tibetan Plateau remains elusive. Here we investigate the Cenozoic thermal histories of rocks along the eastern margin of the plateau adjacent to the Sichuan Basin in an effort to determine when the steep topographic escarpment that characterizes this margin developed. Temperature-time paths inferred from ^(40)Ar/^(39)Ar thermochronology of biotite, multiple diffusion domain modeling of alkali feldspar ^(40)Ar release spectra, and (U-Th)/He thermochronology of zircon and apatite imply that rocks at the present-day topographic front of the plateau underwent slow cooling (<1\u00b0C/m.y.) from Jurassic times until the late Miocene or early Pliocene. The regional extent and consistency of thermal histories during this time period suggest the presence of a stable thermal structure and imply that regional denudation rates were low (<0.1 mm/yr for nominal continental geotherms). Beginning in the late Miocene or early Pliocene, these samples experienced a pronounced cooling event (>30\u00b0\u201350\u00b0C/m.y.) coincident with exhumation from inferred depths of \u223c8\u201310 km, at denudation rates of 1\u20132 mm/yr. Samples from the interior of the plateau continued to cool relatively slowly during the same time period (\u223c3\u00b0C/m.y.), suggesting limited exhumation (1\u20132 km). However, these samples record a slight increase in cooling rate (from <1 to \u223c3\u00b0C/m.y.) at some time during the middle Tertiary; the tectonic significance of this change remains uncertain. Regardless, late Cenozoic denudation in this region appears to have been markedly heterogeneous, with the highest rates of exhumation focused at the topographic front of the plateau margin. We infer that the onset of rapid cooling at the plateau margin reflects the erosional response to the development of regionally significant topographic gradients between the plateau and the stable Sichuan Basin and thus marks the onset of deformation related to the development of the Tibetan Plateau in this region. The present margin of the plateau adjacent to and north of the Sichuan Basin is apparently no older than the late Miocene or early Pliocene (\u223c5\u201312 Ma).", "date": "2002-01", "date_type": "published", "publication": "Tectonics", "volume": "21", "number": "1", "publisher": "American Geophysical Union", "pagerange": "Art. No. 1001", "id_number": "CaltechAUTHORS:20130313-131557163", "issn": "0278-7407", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130313-131557163", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF Continental Dynamics Program", "grant_number": "EAR-9614970" }, { "agency": "NSF Continental Dynamics Program", "grant_number": "EAR-9725723" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2000TC001246", "primary_object": { "basename": "2000TC001246.pdf", "url": "https://authors.library.caltech.edu/records/sbvw8-v9r46/files/2000TC001246.pdf" }, "resource_type": "article", "pub_year": "2002", "author_list": "Kirby, Eric; Reiners, Peter W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/hj5ze-gq998", "eprint_id": 35499, "eprint_status": "archive", "datestamp": "2023-08-22 01:18:59", "lastmod": "2024-01-13 05:56:56", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Stockli-D-F", "name": { "family": "Stockli", "given": "Daniel F." } } ] }, "title": "(U-Th)/He Dating of Phosphates: Apatite, Monazite, and Xenotime", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2002 Mineralogical Society of America. We thank Barry Kohn and Peter Zeitler for helpful comments.", "abstract": "The common phosphate minerals, apatite Ca_5(PO_4)_3(F,OH,Cl), monazite\n(Ce,La,Th)PO_4, and xenotime YPO_4, have found widespread use in geochronology\nbecause they incorporate U and Th into their structures. For example, apatite usually has\na few tens of ppm of both U and Th, while monazite and xenotime usually have hundreds\nof ppm to weight percent levels of these elements. As a consequence, these phosphates\ncan be dated using several fundamentally different isotopic techniques. Elsewhere in this\nvolume Harrison et al. describe phosphate dating using ingrowth of radiogenic Pb, the\nfinal daughter of U and Th series decay, and Gleadow et al. describe dating based on\ndamage tracks from the spontaneous fission of ^(238)U. The most recently developed dating\ntechnique applied to phosphates, described in this chapter, uses the accumulation of\n\u03b1 particles from U and Th series decay, (U-Th)/He dating. While phosphate U-Th-Pb\ndating is usually used to date high temperature events such as crystallization of igneous\nrocks and the timing of prograde metamorphism, fission track and (U-Th)/He dating are\nmore commonly used to establish cooling histories through low temperatures, for\nexample, in the range ~110-40\u00b0C in the case of apatite.\n\nDating of minerals using radiogenic He was first explored shortly after the discovery\nof radioactivity (Strutt 1908) and was investigated extensively in the 1950s and 1960s,\nmostly on very U- and Th-rich minerals such as zircon and titanite (Hurley 1952, 1954;\nDamon and Kulp 1957, Damon and Green 1963). Apatite He dating was first investigated\nby Zeitler et al. (1987), who studied the diffusion rate of He from apatite and proposed\nthat apatite He dating might provide a useful thermochronometer, recording cooling\nthrough about 100\u00b0C. Further studies both in the laboratory (Lippolt et al. 1994, Wolf et\nal. 1996b, Warnock et al. 1997, Farley 2000) and in the natural setting (House et al. 1999,\nStockli et al. 2000) have confirmed this idea, and the technique has now been applied to a\nrange of tectonic, geologic and geomorphologic problems (e.g., House et al. 1997, 1998;\nSpotila et al. 1997, Farley et al. 2001, Stockli et al. 2000). Monazite and xenotime have\nonly recently come under scrutiny for He geochronology (e.g., Pik and Marty 1999), and\nlittle is yet known of their potential for routine geo- or thermochronometry.", "date": "2002", "date_type": "published", "publisher": "Mineralogical Society of America", "place_of_pub": "Washington, DC", "pagerange": "559-577", "id_number": "CaltechAUTHORS:20121116-075945167", "isbn": "9780939950607", "book_title": "Phosphates: Geochemical, Geobiological, and Materials Importance", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121116-075945167", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Kohn-M-J", "name": { "family": "Kohn", "given": "Matthew J." } }, { "id": "Rakovan-J", "name": { "family": "Rakovan", "given": "John" } }, { "id": "Hughes-J-M", "name": { "family": "Hughes", "given": "John M." } } ] }, "doi": "10.2138/rmg.2002.48.15", "resource_type": "book_section", "pub_year": "2002", "author_list": "Farley, Kenneth A. and Stockli, Daniel F." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/v6k9b-p3y06", "eprint_id": 35500, "eprint_status": "archive", "datestamp": "2023-08-22 01:19:08", "lastmod": "2024-01-13 05:56:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "(U-Th)/He Dating: Techniques, Calibrations, and Applications", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2002 Mineralogical Society of America. Many members of my research group, especially M. House, P. Reiners, D. Stockli, and R. Wolf, contributed substantially to the ideas and content of this paper. This work was supported by the National Science Foundation and by a fellowship award from the David and Lucille Packard Foundation. Fin Stuart, Raphael Pik and Tibor Dunai\nprovided helpful reviews.", "abstract": "The possibility of dating minerals by the accumulation of ^4He from U and Th decay\nhas been recognized for many years (e.g., Strutt 1905), but in the century since the idea\nwas first conceived, the method has rarely been applied successfully. After several\ninvestigations of (U-Th)/He dating of various minerals (e.g., Damon and Kulp 1957;\nFanale and Kulp 1962; Damon and Green 1963; Turekian et al. 1970; Bender 1973;\nLeventhal 1975; Ferreira et al. 1975) the technique was essentially abandoned as yielding\nunreliable and usually low ages, presumably as a result of diffusive He loss possibly\nassociated with radiation damage. In 1987, Zeitler and coworkers rekindled interest in the\nmethod by proposing that in the case of apatite, He ages might be meaningfully\ninterpreted as ages of cooling through very low temperatures. Laboratory diffusion data\npresented by these authors indicated a closure temperature of about 100\u00baC, a value\nsupported by more recent studies (Lippolt et al. 1994; Wolf et al. 1996b; Warnock et al.\n1997). Consistent with this interpretation Wolf et al. (1996a) found that apatite He ages\nincrease systematically with sample elevation in a mountain range, as expected for\nexhumation-induced cooling through a low closure temperature. Based on the strength of\nthese results and additional laboratory (Farley 2000) and natural (Warnock et al. 1997;\nHouse et al. 1999; Stockli et al. 2000) constraints on He diffusivity, recent attention has\nfocused on applications of apatite He thermochronometry. There is also renewed interest\nin He dating of other U- and Th-bearing minerals both for dating mineral formation and\nfor thermochronometry. For example, Lippolt and coworkers have undertaken detailed\nstudies of He diffusion and dating of various phases, most notably hematite formed in\nhydrothermal systems (Lippolt and Weigel 1988; Wernicke and Lippolt 1992; Lippolt et\nal. 1993; Wernicke and Lippolt 1994a,b).\nHere I present an overview of recent techniques, calibrations, and applications of the\n(U-Th)/He dating method; Hurley (1954) provides an excellent summary of earlier work in\nthis field. Much of this paper focuses on apatite, because the He behavior and requisite\nanalytical techniques are better established for this phase than for other target minerals,\nsuch as zircon and titanite. Similarly, much of this paper concerns He diffusivity behavior\nrequired for thermochronometric applications, yet recent work is also considering applications\nto direct dating, for example, of young tephras (Farley et al. 2001).", "date": "2002", "date_type": "published", "publisher": "Mineralogical Society of America", "place_of_pub": "Washington, DC", "pagerange": "819-844", "id_number": "CaltechAUTHORS:20121116-080830444", "isbn": "9780939950591", "book_title": "Noble Gases in Geochemistry and Cosmochemistry", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121116-080830444", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" }, { "agency": "David and Lucille Packard Foundation" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Porcelli-D", "name": { "family": "Porcelli", "given": "Donald" } }, { "id": "Ballentine-C-J", "name": { "family": "Ballentine", "given": "Chris J." } }, { "id": "Wieler-R", "name": { "family": "Wieler", "given": "Rainer" } } ] }, "doi": "10.2138/rmg.2002.47.18", "resource_type": "book_section", "pub_year": "2002", "author_list": "Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3xgjg-3xn61", "eprint_id": 35397, "eprint_status": "archive", "datestamp": "2023-08-22 01:17:37", "lastmod": "2023-10-20 16:10:54", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Batt-G-E", "name": { "family": "Batt", "given": "Geoffrey E." } }, { "id": "Brandon-M-T", "name": { "family": "Brandon", "given": "Mark T." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Roden-Tice-M", "name": { "family": "Roden-Tice", "given": "Mary" } } ] }, "title": "Tectonic synthesis of the Olympic Mountains segment of the Cascadia wedge, using two-dimensional thermal and kinematic modeling of thermochronological ages", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2001 by the American Geophysical Union.\nReceived 10 August 2000; accepted 25 April 2001.\nThis work was completed while G.B. was funded\nby a Damon Wells postdoctoral fellowship at Yale University. Detailed and thorough reviews of this manuscript by Peter Reiners and Phil Armstrong helped to significantly improve the clarity of our arguments.\n\nPublished - 2001JB000288.pdf
Erratum - 2003JB002897.pdf
", "abstract": "A fully coupled two-dimensional kinematic and thermal model of a steady state accretionary wedge, constrained by an extensive data set of fission track and (U-Th)/He ages for apatite and zircon, is here used to investigate the development of the Olympic Mountains segment of the Cascadia accretionary wedge. The model has two main free parameters: \u03b5_(max), the maximum rate of erosion for a generic erosion function operating at the top of the wedge, and \u03b1, the distribution of sedimentary accretion into the wedge. The best fit values for \u03b5_(max) and \u03b1 and their confidence limits are determined through an iterative search of parameter space. This study represents the first time that such inversion methods have been used to quantify the thermal-kinematic evolution of an accretionary wedge. Our results suggest that horizontal transport plays an important role in the exhumation trajectories experienced by material passing through the Cascadia wedge. At a 95% confidence interval, 80 to 100% of the sedimentary sequence from the subducting Juan de Fuca Plate has been accreted at the front of the wedge offshore of the Olympics over the past 14 m.y. This frontally accreted material must then traverse the entire width of the wedge prior to its eventual exposure in the Olympic forearc high. Assessed in this two-dimensional framework, the fission track and (U-Th)/He age data sets from the Olympic Mountains are all best fit by \u03b5_(max) of 0.9\u20131.0 mm yr^(\u22121), despite variation in the timescales relevant to the three chronometers. This result supports the hypothesis that the Olympic Mountains segment of the Cascadia accretionary wedge has been in a flux steady-state since \u223c14 Ma. The demonstration of a flux balance across the Cascadia margin also suggests that margin-parallel transport has not had a significant role in driving uplift of the Olympic Mountains.", "date": "2001-11-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "106", "number": "B11", "publisher": "American Geophysical Union", "pagerange": "26731-26746", "id_number": "CaltechAUTHORS:20121109-141537734", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121109-141537734", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Yale University Damon Wells Postdoctoral Fellowship" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2001JB000288", "primary_object": { "basename": "2001JB000288.pdf", "url": "https://authors.library.caltech.edu/records/3xgjg-3xn61/files/2001JB000288.pdf" }, "related_objects": [ { "basename": "2003JB002897.pdf", "url": "https://authors.library.caltech.edu/records/3xgjg-3xn61/files/2003JB002897.pdf" } ], "resource_type": "article", "pub_year": "2001", "author_list": "Batt, Geoffrey E.; Brandon, Mark T.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/hj8xv-77674", "eprint_id": 35710, "eprint_status": "archive", "datestamp": "2023-08-22 01:16:13", "lastmod": "2023-10-20 20:30:56", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Mukhopadhyay-S", "name": { "family": "Mukhopadhyay", "given": "S." } } ] }, "title": "An Extraterrestrial Impact at the Permian-Triassic Boundary?", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2001 American Association for the Advancement of Science.\n\nReceived 27 April 2001; accepted 17 August 2001.", "abstract": "Becker et al. (1) presented geochemical evidence that suggests that the largest mass extinction in Earth history, at the Permian-Triassic boundary (PTB) 250 million years ago (Ma), coincided with an extraterrestrial impact comparable in size to the one that likely caused the end-Cretaceous extinctions 65 Ma (2). Although Becker et al. analyzed material from sections in Hungary, Japan, and China, the Hungarian section yielded no extraterrestrial signature, and their identification of the PTB in the Japanese section is questioned in the accompanying comment by Isozaki (below). Thus, only their analyses of the Chinese section provide hitherto uncontested evidence for an impact at the boundary\u2014in the form of data on the abundance and composition of fullerenes in the \"boundary clay,\" a volcanic ash layer called Bed 25 at Meishan, China (3). Although fullerenes may be purely terrestrial [see, e.g., (4)], Becker et al. report that the fullerenes from the Meishan ash carry extraterrestrial noble gases in the cage structure, rich in ^(3)He and with distinctive ^(3)He/^(36)Ar and ^(40)Ar/^(36)Ar ratios, and that this signature therefore derived from a bolide impact. Here, we report that we are able to detect fullerene-hosted extraterrestrial ^(3)He neither in aliquots of the same Meishan material analyzed by Beckeret al., nor any in samples of a second Chinese PTB section, and that we thus find no evidence for an impact.", "date": "2001-09-28", "date_type": "published", "publication": "Science", "volume": "293", "number": "5539", "publisher": "American Association for the Advancement of Science", "pagerange": "2343", "id_number": "CaltechAUTHORS:20121128-132918348", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121128-132918348", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.293.5539.2343a", "resource_type": "article", "pub_year": "2001", "author_list": "Farley, K. A. and Mukhopadhyay, S." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/wekxe-nmk37", "eprint_id": 35438, "eprint_status": "archive", "datestamp": "2023-08-22 01:14:06", "lastmod": "2023-10-20 16:20:13", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Reiners-P-W", "name": { "family": "Reiners", "given": "Peter W." }, "orcid": "0000-0001-7240-2373" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Influence of crystal size on apatite (U-Th)/He\n thermochronology: an example from the Bighorn Mountains, Wyoming", "ispublished": "pub", "full_text_status": "restricted", "keywords": "thermochronology; exhumation; helium; Laramide Orogeny; Th/U; U/He", "note": "\u00a9 2001 Elsevier Science B.V. Received 28 November 2000; received in revised form 23 March 2001; accepted 3 April 2001. We gratefully acknowledge the collaboration of\nthe 1999 Keck-Bighorn participants (especially Peter Crowley, Joanna Reuter, and Grant Kaye), and Cathy Manduca. Thanks also to Charles Knaack for valuable technical assistance at WSU. We appreciate helpful reviews by Terry\nSpell and Peter Zeitler. This work was supported in part by NSF Grant EAR 0073576 to P.W.R.[RV]", "abstract": "Near-surface tectonic and geomorphic processes involve cooling of rocks through low temperatures (50\u2013200\u00b0C). Because rates of helium diffusion in apatite, titanite, and zircon are sensitive to temperature variations in this range, uranium\u2013thorium/helium thermochronometry ((U\u2013Th)/He dating) is well-suited to establishing the timing and rates of these processes in the geologic record. However, because fractional loss of He is controlled by crystal size such that larger crystals retain a larger fraction of radiogenic He, (U\u2013Th)/He ages must vary not only with thermal history but also with crystal size. Here we present crystal size-correlated He ages from co-existing apatites from the Bighorn Mountains, Wyoming that range from 100 to 350 Ma. These correlations are a sensitive indicator of the rock's thermal history in a temperature range below the system's nominal closure temperature (T_c\u223c70\u00b0C for apatite), and are consistent with a thermal history involving residence in the upper 2\u20133 km of crust since the Precambrian, with maximum temperatures of 65\u201380\u00b0C just prior to Laramide orogenic exhumation. The influence of crystal size on He ages will be most apparent in rocks where temperatures have been in the range of partial He retention for long periods of time (\u223c30\u201370\u00b0C for >10^7 years). In such cases, accurate interpretation of (U\u2013Th)/He ages must incorporate the effect of crystal size, and this method may provide insights to thermal histories of rocks in previously inaccessible low-temperature ranges.", "date": "2001-06-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "188", "number": "3-4", "publisher": "Elsevier", "pagerange": "413-420", "id_number": "CaltechAUTHORS:20121113-131731135", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121113-131731135", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR 0073576" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(01)00341-7", "resource_type": "article", "pub_year": "2001", "author_list": "Reiners, Peter W. and Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/zjxp1-cfq83", "eprint_id": 35437, "eprint_status": "archive", "datestamp": "2023-08-22 01:13:58", "lastmod": "2023-10-20 16:20:04", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Renne-P-R", "name": { "family": "Renne", "given": "Paul R." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Becker-T-A", "name": { "family": "Becker", "given": "Tim A." } }, { "id": "Sharp-W-D", "name": { "family": "Sharp", "given": "Warren D." } } ] }, "title": "Terrestrial cosmogenic argon", "ispublished": "pub", "full_text_status": "restricted", "keywords": "cosmogenic elements; argon; isotopes", "note": "\u00a9 2001 Elsevier Science B.V. Received 28 December 2000; accepted 3 April 2001. We thank the Hawaii Scientific Drilling Project, J.N. Christensen and J.J. Donovan for various 'baseline' samples; P.G. Fitzgerald for the Trans-antarctic samples; B.M. Kennedy, K. Min and K.B. Knight for discussion and suggestions on the manuscript; F.M. Phillips for a preprint of a paper cited herein; D. Lal and an anonymous referee for constructive reviews of the manuscript. We dedicate this paper to the late Prof. John H.\nReynolds.[EB]", "abstract": "Cosmogenically enriched ^(38)Ar/^(36)Ar ratios are detectable in Ca-bearing terrestrial samples, and are resolvable from a uniform background value of 0.18826\u00b10.00018 for materials lacking nucleogenic or kinetic mass fractionation effects. Relationships between ^(38)Ar/^(36)Ar and cosmogenic ^3He in apatite and fluorite are systematic but difficult to reconcile with current estimates of terrestrial production rates for ^(38)Ar and ^(36)Ar from Ca, suggesting that production from Cl and/or other targets is significant, or that the estimates are inaccurate. In either case, the effects of time-varying production of ^(36)Ar from \u03b2^\u2212 decay of cosmogenic ^(36)Cl produced from Ca, K, or Cl on the ^(38)Ar/^(36)Ar ratio must be accounted for.", "date": "2001-06-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "188", "number": "3-4", "publisher": "Elsevier", "pagerange": "435-440", "id_number": "CaltechAUTHORS:20121113-130518124", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121113-130518124", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(01)00336-3", "resource_type": "article", "pub_year": "2001", "author_list": "Renne, Paul R.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/chhgq-2hn79", "eprint_id": 36545, "eprint_status": "archive", "datestamp": "2023-08-22 01:11:22", "lastmod": "2023-10-20 23:16:59", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mukhopadhyay-S", "name": { "family": "Mukhopadhyay", "given": "S." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Montanari-A", "name": { "family": "Montanari", "given": "A." } } ] }, "title": "A Short Duration of the Cretaceous-Tertiary Boundary Event: Evidence from Extraterrestrial Helium-3", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2001 American Association for the Advancement of Science.\n\nReceived for publication 16 November 2000; accepted for publication 1 February 2001.\n\nWe thank J. Kirschvink and T. Raub for providing the STW samples (sample collection funded by NSF EAR9807741) and F. Robaszynski for discussion on the STW section. Funded by NASA and the David and Lucille Packard Foundation.\n\nSupplemental Material - Mukhopad3.sup.pdf
", "abstract": "Analyses of marine carbonates through the interval 63.9 to 65.4 million years ago indicate a near-constant flux of extraterrestrial helium-3, a tracer of the accretion rate of interplanetary dust to Earth. This observation indicates that the bolide associated with the Cretaceous-Tertiary (K-T) extinction event was not accompanied by enhanced solar system dustiness and so could not have been a member of a comet shower. The use of helium-3 as a constant-flux proxy of sedimentation rate implies deposition of the K-T boundary clay in (10 \u00b1 2) \u00d7 10^3 years, precluding the possibility of a long hiatus at the boundary and requiring extremely rapid faunal turnover.", "date": "2001-03-09", "date_type": "published", "publication": "Science", "volume": "291", "number": "5510", "publisher": "American Association for the Advancement of Science", "pagerange": "1952-1955", "id_number": "CaltechAUTHORS:20130123-134854180", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130123-134854180", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR9807741" }, { "agency": "NASA" }, { "agency": "David and Lucille Packard Foundation" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.291.5510.1952", "primary_object": { "basename": "Mukhopad3.sup.pdf", "url": "https://authors.library.caltech.edu/records/chhgq-2hn79/files/Mukhopad3.sup.pdf" }, "resource_type": "article", "pub_year": "2001", "author_list": "Mukhopadhyay, S.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/mbky3-s5g65", "eprint_id": 35561, "eprint_status": "archive", "datestamp": "2023-08-22 01:10:08", "lastmod": "2023-10-20 19:08:39", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mukhopadhyay-S", "name": { "family": "Mukhopadhyay", "given": "S." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Montanari-A", "name": { "family": "Montanari", "given": "A." } } ] }, "title": "A 35 Myr record of helium in pelagic limestones from Italy: Implications for interplanetary dust accretion from the early Maastrichtian to the middle Eocene", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2001 Elsevier Science Ltd. Received May 30, 2000; accepted in revised form September 13, 2000. Associate editor: C. Koeberl. We thank Kim Robinson, Elizabeth Navarro, and Selene Eltgroth for sample preparation and P. Clayes, B. Peucker-Ehrenbrink, and B. Schmitz for thorough and helpful reviews. This was work was supported by NASA.", "abstract": "We have determined the helium concentration and isotopic composition of a suite of early Maastrichtian through middle Eocene pelagic limestones in the Italian Apennines. The results provide a 35 Myr record of the implied flux of extraterrestrial ^3He, which is a proxy for the accretion rate of interplanetary dust particles (IDPs).\nOur measurements show that the ^3He flux was fairly constant in the Maastrichtian, except for possible minor increases (factor of two or less) from \u223c70.5 Ma to 68 Ma and at \u223c66 Ma, which probably reflect transient increases in the accretion rate of asteroidal and/or cometary IDPs. We find no evidence for an increase in IDP accretion at or immediately before the K/T boundary, implying that the K/T impact was not associated with enhanced solar system dustiness. This observation precludes the possibility that the K/T impactor was a member of a major comet shower, and is more consistent with impact of a lone comet or asteroid. Our data suggest a 2 to 4 fold increase in IDP accretion between 57 and 54 Ma, followed by a factor of three decrease over an \u223c4 Myr period in the early to middle Eocene. The duration and magnitude of this variability is inconsistent with previous observations attributed to a shower of long period comets, and is more likely the result of collisions in the asteroid belt/and or Kuiper belt. In the entire 35 Myr record we find no evidence for major enhancements of the IDP accretion rate of the type expected from comet showers. Our results, in combination with earlier ^3He measurements, do not support models that predict recurrent comet showers with periods of <38 Myrs. If there is a periodicity in the cratering record that is caused by periodic modulation of the Oort cloud, it is not evident in the Apennine sediment data.\nAlong with the ^3He measurements we also obtained ^4He concentrations, which record temporal changes in the flux or composition of terrigenous matter. The most significant change in ^4He occurs in the last 4 Myrs of the Cretaceous, over which the concentration of ^4He in the detrital component rises by 300%. This rise tracks a strong increase in the seawater ^(87)Sr/^(86)Sr ratio, suggesting a globally significant change in the composition of continental detritus delivered to the oceans, possibly arising from increased continental weathering.", "date": "2001-02-15", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "65", "number": "4", "publisher": "Elsevier", "pagerange": "653-669", "id_number": "CaltechAUTHORS:20121120-102333961", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-102333961", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0016-7037(00)00555-X", "resource_type": "article", "pub_year": "2001", "author_list": "Mukhopadhyay, S.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/70g3w-2pa96", "eprint_id": 35432, "eprint_status": "archive", "datestamp": "2023-08-22 01:09:59", "lastmod": "2023-10-20 16:19:46", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Cerling-T-E", "name": { "family": "Cerling", "given": "T. E." } }, { "id": "Fitzgerald-P-G", "name": { "family": "Fitzgerald", "given": "P. G." } } ] }, "title": "Cosmogenic ^3He in igneous and fossil tooth enamel \n fluorapatite", "ispublished": "pub", "full_text_status": "restricted", "keywords": "exposure age; cosmogenic elements; He-3; apatite; teeth; enamel; Transantarctic Mountains", "note": "\u00a9 2001 Elsevier Science B.V. Received 2 August 2000; received in revised form 21 November 2000; accepted 22 November 2000. Thanks to Adam Kent for the Li measurements\nand J\u00f6rg Sch\u00e4fer and Fin Stuart for helpful reviews.\nThis work was supported by the NSF and a fellowship from the David and Lucille Packard Foundation to K.A.F.[AH]", "abstract": "Igneous fluorapatite samples from a suite of six granitic rocks from the Transantarctic Mountains have high ^3He concentrations (to 5\u00d710^9 atoms g^(\u22121)) and high ^3He/^4He ratios (to 9\u00d710^(\u22127)). These values are far higher than those found in several hundred igneous apatites from elsewhere around the world and are higher than can be attributed to nuclear reactions on ^6Li. This ^3He is almost certainly derived from cosmic ray reactions in rocks with high exposure ages at high latitude and elevation. Several samples of fossil tooth enamel fluorapatite from the Turkana Basin of Kenya are similarly rich in ^3He, with up to 1\u00d710^7 atoms ^3He g^(\u22121) and ^3He/^4He ratios up to 4\u00d710^(\u22126). Again, this ^3He is most logically attributed to cosmic ray reactions. Provided that cosmogenic ^3He, like radiogenic ^4He, is quantitatively retained in fluorapatite under Earth surface conditions, routine ^3He exposure dating of this common phase may be possible. Based on its chemical composition, the ^3He production rate in fluorapatite is about 100 atoms g^(\u22121) yr^(\u22121) at sea level and high latitude. Using this rate the apatites from the Transantarctic Mountains have apparent exposure ages of 0.5\u20136.2 Myr, in agreement with values elsewhere in the range. The fossil tooth enamel samples have apparent exposure ages ranging from a few up to 130 kyr. Such high exposure ages suggest some of these fossils may be lag deposits with a very long residence time at or near the Earth's surface. ^3He exposure ages can provide insights to the depositional and reworking history of enamel-bearing fossils. At present the major limitations to ^3He exposure dating of fluorapatite are purification of sufficient amounts of material and measurement of small amounts of ^3He in the presence of large quantities of ^4He. In addition, further work is necessary to establish the nucleogenic ^3He background in fluorapatite.", "date": "2001-02-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "185", "number": "1-2", "publisher": "Elsevier", "pagerange": "7-14", "id_number": "CaltechAUTHORS:20121113-114436342", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121113-114436342", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" }, { "agency": "David and Lucille Packard Foundation" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(00)00360-5", "resource_type": "article", "pub_year": "2001", "author_list": "Farley, K. A.; Cerling, T. E.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/xanpf-jy338", "eprint_id": 35442, "eprint_status": "archive", "datestamp": "2023-08-22 01:09:15", "lastmod": "2023-10-20 16:20:32", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "House-M-A", "name": { "family": "House", "given": "Martha A." } }, { "id": "Wernicke-B-P", "name": { "family": "Wernicke", "given": "Brian P." }, "orcid": "0000-0002-7659-8358" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Paleo-Geomorphology of the Sierra Nevada, California, from (U-TH)/He Ages in Apatite", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2001 by American Journal of Science. We wish to thank the people at Yosemite and Sequoia-Kings Canyon National\nParks for making the necessary sample collection possible. We also thank J. Kelley of El\nAero for assistance in collection of the T2 transect. Funding for this study was provided\nby the National Science Foundation (EAR-9909453 to Wernicke; EAR-9633381 and\nEAR-9526895 to Wernicke and Farley). This manuscript benefited greatly from thoughtful\nreviews by P. Reiners, J. Spotila, and J. Wakabayashi.", "abstract": "New apatite (U-Th)/He ages from the central Sierra Nevada, California, place limits on the morphology and evolution of longitudinal profiles of major transverse river drainages developed in the Late Cretaceous. Helium ages from a new orogen-parallel, constant-elevation sample transect are relatively uniform (\u223c60 Ma) and not correlated with topography, unlike those from a similar, lower elevation transect approx 15 km to the west. We interpret the marked difference in the two orogen-parallel profiles to reflect a headward decrease in long-wavelength, transverse relief at the time of cooling, consistent with either a concave-up stream gradient, typical of those observed near the headwaters of modern Sierran trunk streams, or a convex gradient like those found along slope breaks of eroding plateau edges. From the San Joaquin drainage we obtained a new helium age-versus-elevation profile, which has a comparable slope to those previously reported for the Yosemite Valley, Kings Canyon, and Mt. Whitney areas. This new profile yields slightly older ages at a given elevation as expected from its position adjacent to the largest major drainage. The age versus elevation profiles imply that the mean denudation rate of the region in the Cenozoic was about 0.04 to 0.05 mm/yr. We show that long-wavelength (\u03bb = 70 km) relief inferred from longitudinal helium age variations is a strong function of erosion rate, such that even relatively subdued relief is detectable with helium age profiling provided that denudation rates were low. Using the rate implied by Sierran age-versus-elevation profiles, we infer long-wavelength relief of 1500 \u00b1 500 m in the Late Cretaceous. By analogy with modern orogenic plateaus, this value of long-wavelength relief suggests a Cretaceous interior Cordilleran plateau lay at an elevation of at least 3000 m.", "date": "2001-02", "date_type": "published", "publication": "American Journal of Science", "volume": "301", "number": "2", "publisher": "American Journal of Science", "pagerange": "77-102", "id_number": "CaltechAUTHORS:20121113-153928813", "issn": "0002-9599", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121113-153928813", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9909453" }, { "agency": "NSF", "grant_number": "EAR-9633381" }, { "agency": "NSF", "grant_number": "EAR-9526895" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.2475/ajs.301.2.77", "resource_type": "article", "pub_year": "2001", "author_list": "House, Martha A.; Wernicke, Brian P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/nyj71-n3g36", "eprint_id": 36884, "eprint_status": "archive", "datestamp": "2023-08-22 01:09:23", "lastmod": "2023-10-23 15:53:52", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Rusmore-M-E", "name": { "family": "Rusmore", "given": "M. E." } }, { "id": "Bogue-S-W", "name": { "family": "Bogue", "given": "S. W." } } ] }, "title": "Post\u201310 Ma uplift and exhumation of the northern Coast Mountains, British Columbia", "ispublished": "pub", "full_text_status": "restricted", "keywords": "uplift, Coast Mountains, helium age, exhumation, apatite", "note": "\u00a9 2001 Geological Society of America.\nManuscript received May 26, 2000.\nRevised manuscript received October 12, 2000.\nManuscript accepted October 26, 2000.\nWe thank P. Molnar and P. Umhoefer for helpful reviews, R.S. Anderson,\nM. House, G. Woodsworth, and P. O'Sullivan for discussions, L. Hedges for\ncareful analytical work, and K. Dodson, R. Karpilo, and J. Robinson for field\nassistance. G. Woodsworth led sample collection on Mount Elizabeth. This work\nwas supported by National Science Foundation grants EAR-9805124 and EAR-9807740.", "abstract": "Apatite (U-Th)/He ages reveal three distinct periods in the exhumation history of the northern Coast Mountains (\u223c54\u00b0N). A well-developed helium partial retention zone indicates little or no exhumation between ca. 30 and 10 Ma. Beginning at 10 Ma and extending to at least 4 Ma the range underwent steady but slow exhumation of \u223c0.22 mm/yr, after which the exhumation rate increased by at least 70%. An 85-km-long He age traverse across the orogen at sea level shows that vertical offsets on post-10 Ma faults are minor. Furthermore, the sea-level He ages (14\u20132.8 Ma) inversely correlate with local mean elevation along the traverse. These data suggest that the Coast Mountains first appeared as a significant topographic feature only within the past few million years. This history is not consistent with suggestions that uplift of the range resulted from formation of the Queen Charlotte basin in early-middle Miocene time. We speculate that intense erosion by alpine and continental glaciation after 2.5 Ma triggered isostatic uplift and creation of the modern topography of the Coast Mountains.", "date": "2001-02", "date_type": "published", "publication": "Geology", "volume": "29", "number": "2", "publisher": "Geological Society of America", "pagerange": "99-102", "id_number": "CaltechAUTHORS:20130212-141652973", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130212-141652973", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9805124" }, { "agency": "NSF", "grant_number": "EAR-9807740" } ] }, "other_numbering_system": { "items": [ { "id": "200115", "name": "Data Repository item" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/0091-7613(2001)029<0099:PMUAEO>2.0.CO;2", "resource_type": "article", "pub_year": "2001", "author_list": "Farley, K. A.; Rusmore, M. E.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/2ar1s-x4x40", "eprint_id": 35485, "eprint_status": "archive", "datestamp": "2023-08-22 01:07:21", "lastmod": "2023-10-20 16:24:21", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Extraterrestrial Helium in Seafloor Sediments:\n Identification, Characteristics, and Accretion Rate\n Over Geologic Time", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2001 Kluwer Academic/Plenum Publishers.\nI thank Sujoy Mukhopadhyay for thoughtful discussions, and for sample analyses and\ndata preparation for the Gubbio section. Careful reviews by Franco Marcantonio and\nSteve Kortenkamp improved the manuscript. D. Lal provided the Chinese loess samples.\nThis work was supported by NASA and a fellowship from the David and Lucille Packard Foundation.", "abstract": "Almost 40 years after the discovery of extraterrestrial helium in seafloor sediments,\nrenewed attention is being focused on using helium as a proxy for the sedimentary\nabundance of extraterrestrial debris. Extraterrestrial He is carried to the seafloor by\nthe finest fraction of interplanetary dust and is retained in at least some sediments for\nhundreds of millions of years. Helium isotope systematics uniquely identity the\nextraterrestrial component, which is apparently hosted within magnetite and silicate\ngrains. In some sediments ^3He is completely derived from this source, in others the\nextraterrestrial fraction can be computed from the measured ^3He/^4He ratio. Variations\nin the sedimentary concentration of extraterrestrial ^3He must reflect both changes in\nsedimentation rate and fluctuations in the accretion rate of ^3He from space. When\nchanges in sedimentation rate can be controlled for, variations in extraterrestrial ^3He\ncan be related to changes in the accretion rate of IDPs arising from major solar system\nevents including asteroid collisions and enhanced cometary activity. A ^3He\nrecord in sediments spanning the last 70 Myr provides insights to such events, including\nthe first compelling evidence for the occurrence of a shower of long-period\ncomets, 35 Ma.", "date": "2001", "date_type": "published", "publisher": "Kluwer Academic/Plenum Publishers", "place_of_pub": "New York", "pagerange": "179-204", "id_number": "CaltechAUTHORS:20121115-103034876", "isbn": "9780306466892", "book_title": "Accretion of Extraterrestrial Matter Throughout Earth's History", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121115-103034876", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" }, { "agency": "David and Lucille Packard Foundation" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Peucker-Ehrenbrink-B", "name": { "family": "Peucker-Ehrenbrink", "given": "Bernhard" } }, { "id": "Schmitz-B", "name": { "family": "Schmitz", "given": "Birger" } } ] }, "resource_type": "book_section", "pub_year": "2001", "author_list": "Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/yq6t2-ty028", "eprint_id": 35431, "eprint_status": "archive", "datestamp": "2023-08-22 01:06:37", "lastmod": "2023-10-20 16:12:42", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "House-M-A", "name": { "family": "House", "given": "M. A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Stockli-D", "name": { "family": "Stockli", "given": "D." } } ] }, "title": "Helium chronometry of apatite and titanite using Nd-YAG laser heating", "ispublished": "pub", "full_text_status": "restricted", "keywords": "apatite; titanite; laser methods; thermochronology; helium", "note": "\u00a9 2000 Elsevier Science B.V. Received 8 August 2000; received in revised form 25 September 2000; accepted 27 September 2000. This work was supported by the National Science Foundation and a fellowship to K.A.F. from the David and Lucille Packard Foundation. Helpful reviews by C. Hall and an anonymous reviewer improved the manuscript.[RV].", "abstract": "We developed a technique for extracting ^4He from apatite and titanite using laser heating that permits measurement of U and Th and, hence, (U\u2013Th)/He ages, on a single sample aliquot. Unlike direct laser heating, quantitative He extraction and U, Th retention can be achieved when samples are indirectly laser heated to temperatures below their melting point. Resulting He ages are consistent with those obtained from conventional furnace heating of larger samples. The major advantages of this technique include faster analysis and far lower, more reproducible He blanks that permit single crystal analyses. Single crystal dating opens a variety of new avenues for (U\u2013Th)/He chronometry.", "date": "2000-12-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "183", "number": "3-4", "publisher": "Elsevier", "pagerange": "365-368", "id_number": "CaltechAUTHORS:20121113-113651580", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121113-113651580", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" }, { "agency": "David and Lucile Packard Foundation" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(00)00286-7", "resource_type": "article", "pub_year": "2000", "author_list": "House, M. A.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/vpegp-4m331", "eprint_id": 36750, "eprint_status": "archive", "datestamp": "2023-08-22 01:05:46", "lastmod": "2023-10-23 15:27:21", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Stockli-D-F", "name": { "family": "Stockli", "given": "Daniel F." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Dumitru-T-A", "name": { "family": "Dumitru", "given": "Trevor A." } } ] }, "title": "Calibration of the apatite (U-Th)/He thermochronometer on an exhumed fault block, White Mountains, California", "ispublished": "pub", "full_text_status": "restricted", "keywords": "(U-Th)/He dating, fission-track dating, thermochronology, extensional faulting, White\nMountains.", "note": "\u00a9 2000 Geological Society of America. Manuscript received March 23, 2000. Revised manuscript received July 24, 2000.\nManuscript accepted July 31, 2000. This project was supported by National Science\nFoundation grants EAR-9417937, EAR-9725371 (to E. Miller), and EAR-9805226 (to Farley); a Stanford University McGee grant and a University of California White Mountains Research Station fellowship to Stockli; and a Packard Foundation fellowship to Farley. We thank L. Gilley, L. Hedges, J. Hourigan, and B. Surpless for assistance in the field and laboratory, B. Jones for assistance with electron microprobe work, and the Oregon State University reactor facility for sample irradiation.", "abstract": "This study provides an empirical calibration of the apatite (U-Th)/He thermochronometer using the thermal structure derived from an extensive apatite fission-track study of an exhumed, normal-fault\u2013bounded crustal block in the White Mountains in the western Basin and Range province. This fault block has been tilted \u223c25\u00b0 to the east during extension, exposing a continuous section of rocks previously buried to \u223c7 km. Apatites yield (U-Th)/He apparent ages of ca. 50\u201355 Ma at shallow pre-extensional crustal levels that decrease systematically to ca. 12 Ma at >4.5 km paleodepth. The ages exhibit a well-defined exhumed apatite He partial retention zone over a pre-extensional temperature range of \u223c40\u201380 \u00b0C and are completely reset above 80 \u00b0C, as calibrated from the apatite fission-track data. This pattern is in good agreement with He diffusion behavior predicted by laboratory experiments. The (U-Th)/He and fission-track methods yield concordant estimates for the timing of the onset of extensional faulting in the White Mountains ca. 12 Ma. Given the partially overlapping temperature-sensitivity windows, the (U-Th)/He and fission-track thermochronometers are highly complementary and may be used together to reconstruct thermal histories over the temperature window of \u223c40\u2013110 \u00b0C.", "date": "2000-11", "date_type": "published", "publication": "Geology", "volume": "28", "number": "11", "publisher": "Geological Society of America", "pagerange": "983-986", "id_number": "CaltechAUTHORS:20130204-092017926", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130204-092017926", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9417937" }, { "agency": "NSF", "grant_number": "EAR-9725371" }, { "agency": "NSF", "grant_number": "EAR-9805226" }, { "agency": "Stanford University McGee grant" }, { "agency": "University of California White Mountains Research Station Fellowship" }, { "agency": "Packard Foundation Fellowship" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/0091-7613(2000)28<983:COTAHT>2.0.CO;2", "resource_type": "article", "pub_year": "2000", "author_list": "Stockli, Daniel F.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/smadk-grp71", "eprint_id": 1102, "eprint_status": "archive", "datestamp": "2023-08-22 01:02:47", "lastmod": "2023-10-13 22:37:08", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Burnard-P-G", "name": { "family": "Burnard", "given": "P. G." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Calibration of pressure-dependent sensitivity and discrimination in Nier-type noble gas ion sources", "ispublished": "pub", "full_text_status": "public", "keywords": "Mass spectrometer; noble gases; Instruments and techniques; isotopic composition/chemistry; geochronology", "note": "Copyright 2000 by the American Geophysical Union. \n\nReceived January 8, 2000; Revised May 25, 2000; Accepted June 17, 2000; Published July 18, 2000. \n\nP.B. was funded under the Caltech postdoctoral fellowships program. E.V. Nenow is thanked for technical assistance in automating the half plate voltages. Two anonymous reviewers are thanked for their constructive comments.", "abstract": "The efficiency of many noble gas mass spectrometers to ionize gas species is known to be a function of the pressure of gas in the spectrometer. This work shows how the half plate voltage for maximum He or Ar signal depends on the spectrometer pressure and shows that the half plate voltage for maximum 4He sensitivity does not coincide with the half plate voltage for maximum 3He sensitivity. In addition, half plate voltage has a greater control on sensitivity at higher spectrometer pressures. Variations in He and Ar sensitivity and isotopic discrimination as a function of pressure are due, at least in part, to these variations in the position of maximum sensitivity with respect to half plate voltage. The maximum sensitivity settings shift to lower half plate voltage at high spectrometer pressures, irrespective of if the pressure increase is due to the gas being investigated or a different species. Therefore noble gas mass spectrometers should always be tuned at the maximum possible pressure; measurements at higher pressures should be avoided. Significant errors in the spectrometer sensitivity and discrimination can result from improper tuning and calibration of noble gas mass spectrometers.", "date": "2000-07-18", "date_type": "published", "publication": "Geochemistry, Geophysics, Geosystems", "volume": "1", "number": "7", "publisher": "American Geophysical Union", "pagerange": "2000GC000038", "id_number": "CaltechAUTHORS:BURggg00", "issn": "1525-2027", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:BURggg00", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2000GC000038", "primary_object": { "basename": "BURggg00.pdf", "url": "https://authors.library.caltech.edu/records/smadk-grp71/files/BURggg00.pdf" }, "resource_type": "article", "pub_year": "2000", "author_list": "Burnard, P. G. and Farley, K. A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/t529b-73b32", "eprint_id": 36643, "eprint_status": "archive", "datestamp": "2023-08-22 01:01:02", "lastmod": "2023-10-20 23:26:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Blythe-A-E", "name": { "family": "Blythe", "given": "A. E." } }, { "id": "Burbank-D-W", "name": { "family": "Burbank", "given": "D. W." }, "orcid": "0000-0001-8497-3296" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Fielding-E-J", "name": { "family": "Fielding", "given": "E. J." }, "orcid": "0000-0002-6648-8067" } ] }, "title": "Structural and topographic evolution of the central Transverse Ranges, California, from apatite fission-track, (U-Th)/He and digital elevation model analyses", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2000 Blackwell Science Ltd.\nReceived 16 July 1999; revision accepted 8 May 2000.\nArticle first published online: 24 Dec. 2001.\nThis project was funded by NASA grant (NAG-5-2191) \nto D. Burbank and a Packard Fellowship to K. Farley. \nL. Moresi and W. Featherstone assisted with sample \ncollection on Mt. San Antonio (Mt. Baldy). Reviews by A. Densmore and F. Stuart were helpful and greatly \nappreciated, as were comments by A. Barth.", "abstract": "Apatite fission-track (FT) and (U\u2013Th)/He analyses are used to constrain the low-temperature thermal history of the San Gabriel and San Bernardino Mountains (SGM and SBM), which are part of the southern California Transverse Ranges. FT ages from 33 SGM samples range from 3 to 64 Ma. Helium ages, ranging from 3 to 43 Ma, were obtained from 13 of these samples: all of the He ages are the same or younger than their respective FT ages. FT ages from 10 SBM samples were older, ranging from 45 to 90 Ma. The FT and He data document at least three phases of cooling in the SGM, but only two in the SBM. Prior to ~7 Ma, the thermal history of the SGM appears to have been nearly identical to many of the core complexes in the Basin and Range of south-eastern California: a major phase of cooling is indicated from ~60 to 40 Ma, with a more recent phase beginning at ~23 Ma and continuing until ~10 Ma. The similarity of this timing to that of core complexes suggests that the SGM also originated as a core complex, when the rocks were adjacent to the Chocolate\u2013Orocopia Mountains, and that some of the range-bounding faults were initially extensional. In the SBM, the two phases of cooling documented by the FT data occurred from ~65 to 55 Ma, and from ~18 Ma to the present. The timing on the second phase is very poorly constrained and, therefore, we do not speculate on the origin of the SBM.\n\n\nThe most recent phase of cooling appears to have begun at ~7 Ma in the SGM, as the result of the onset of contractional deformation. A more accelerated phase of cooling may have begun at ~3 Ma. Distinct variations in the total amounts and rates of cooling between different fault-bounded blocks within the SGM are documented since 7 Ma. We use these variations in cooling rates to calculate denudation rates, which are then compared to topographic characteristics for each structural block. These comparisons suggest that more rapid bedrock uplift in the eastern and southern part of the range has strongly affected the present-day physiography. Despite a higher mean elevation, the SBM are much less dissected than the SGM, suggesting that the most recent phase of cooling and bedrock uplift began in the last 3 Myr, much later than the initiation of recent bedrock uplift in the SGM.", "date": "2000-06", "date_type": "published", "publication": "Basin Research", "volume": "12", "number": "2", "publisher": "Blackwell Publishing", "pagerange": "97-114", "id_number": "CaltechAUTHORS:20130129-102819426", "issn": "0950-091X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130129-102819426", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NAG-5-2191" }, { "agency": "David and Lucile Packard Foundation" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1046/j.1365-2117.2000.00116.x", "resource_type": "article", "pub_year": "2000", "author_list": "Blythe, A. E.; Burbank, D. W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/wr8gk-f9115", "eprint_id": 35428, "eprint_status": "archive", "datestamp": "2023-08-22 01:00:45", "lastmod": "2023-10-20 16:12:30", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Reiners-P-W", "name": { "family": "Reiners", "given": "Peter W." }, "orcid": "0000-0001-7240-2373" }, { "id": "Brady-R", "name": { "family": "Brady", "given": "Robert" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Fryxell-J-E", "name": { "family": "Fryxell", "given": "Joan E." } }, { "id": "Wernicke-B-P", "name": { "family": "Wernicke", "given": "Brian" }, "orcid": "0000-0002-7659-8358" }, { "id": "Lux-D", "name": { "family": "Lux", "given": "Daniel" } } ] }, "title": "Helium and argon thermochronometry of the Gold Butte\n block, south Virgin Mountains, Nevada", "ispublished": "pub", "full_text_status": "restricted", "keywords": "thermochronology; Basin and Range Province; exhumation; helium; Ar/Ar; extension", "note": "\u00a9 2000 Elsevier Science B.V. Received 19 November 1999; received in revised form 13 March 2000; accepted 13 March 2000.", "abstract": "One of the largest exposures of Precambrian crystalline rock in the Basin and Range province of the southwestern USA is the Gold Butte block of the south Virgin Mountains, about 15 km west of the Colorado Plateau. It has been interpreted as a largely continuous crustal cross-section about 15\u201320 km thick that was exhumed by a deeply penetrating normal fault during Miocene extension. To test this interpretation as well as the use of the newly developed titanite (U\u2013Th)/He thermochronometer, we examined the low temperature thermal history of the Gold Butte block with the apatite and titanite (U\u2013Th)/He and muscovite ^(40)Ar/^(39)Ar thermochronometers. Apatite He ages average 15.2\u00b11.0 (2\u03c3) Ma throughout the block, indicating that the entire section was warmer than 70\u00b0C prior to Miocene exhumation. Titanite He ages increase from 18.6\u00b11.5 Ma near the paleobottom (west) end of the block, to 195\u00b115 Ma near the paleotop (east) end. A rapid change from mid-Tertiary to increasingly older titanite He ages to the east is observed at about 9.3 km paleodepth, and is interpreted as a fossil He partial retention zone for titanite. Assuming a pre-exhumation geotherm of 20\u00b0C/km (consistent with earlier apatite fission track work), this depth would have corresponded to 196\u00b0C prior to exhumation, indicating that laboratory-derived He diffusion characteristics for titanite that yield a closure temperature of about 200\u00b0C are applicable and correct. Muscovite ^(40)Ar/^(39)Ar ages are 1.0\u20131.4 Ga near the paleotop of the block, and 90 Ma near the paleobottom. Together with ^(207)Pb/^(206)Pb ages on apatite and titanite, and an earlier apatite fission track transect across the Gold Butte block, our data indicate that the continental crust at the western edge of the Colorado Plateau resided at moderate geothermal gradients (and slowly declined in temperature) from 1.4 Ga to about 100\u2013200 Ma. A 90 Ma cooling event clearly affected the mid-crust (deepest portions of Gold Butte), which may reflect accelerated cooling or a brief heating and cooling cycle at this time, after which gradients returned to about 20\u00b0C/km prior to rapid exhumation in the Miocene. This work thus supports previous structural and thermochronologic studies that suggest that the Gold Butte block is the thickest largely continuous cross-section of crust exposed in the southwestern USA.", "date": "2000-05-30", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "178", "number": "3-4", "publisher": "Elsevier", "pagerange": "315-326", "id_number": "CaltechAUTHORS:20121113-112406976", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121113-112406976", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(00)00080-7", "resource_type": "article", "pub_year": "2000", "author_list": "Reiners, Peter W.; Brady, Robert; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/1rj97-m8x95", "eprint_id": 35715, "eprint_status": "archive", "datestamp": "2023-08-22 00:58:24", "lastmod": "2023-10-20 20:31:31", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Axen-G-J", "name": { "family": "Axen", "given": "Gary J." } }, { "id": "Grove-M", "name": { "family": "Grove", "given": "Marty" } }, { "id": "Stockli-D-F", "name": { "family": "Stockli", "given": "Daniel" } }, { "id": "Lovera-O-M", "name": { "family": "Lovera", "given": "Oscar M." } }, { "id": "Rothstein-D-A", "name": { "family": "Rothstein", "given": "David A." } }, { "id": "Fletcher-J-M", "name": { "family": "Fletcher", "given": "John M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth" }, "orcid": "0000-0002-7846-7546" }, { "id": "Abbott-P-L", "name": { "family": "Abbott", "given": "Patrick L." } } ] }, "title": "Thermal evolution of Monte Blanco dome: Low-angle normal faulting during Gulf of California rifting and late Eocene denudation of the eastern Peninsular Ranges", "ispublished": "pub", "full_text_status": "public", "keywords": "Geochemistry: Geochronology; Tectonophysics: Continental tectonics\u2014extensional; Tectonophysics: Continental tectonics\u2014general; Tectonophysics: Plate boundary\u2014general", "note": "\u00a9 2000 American Geophysical Union.\n\nReceived 19 April 1999; accepted 29 October 1999.\n\nFunded by grants from UC MEXUS and UCLA Committee on Research to Axen, from DOE to T.M. Harrison\n(DE-FG-03-89ER14049), from CONACYT to Fletcher (4345-PT), and a Stanford University McGee grant to Stockli. We thank T. Dumitru for helpful discussions and E. Campbell-Stone and P. Umhoefer for thoughtful reviews.\n\nPublished - 1999TC001123.pdf
", "abstract": "Footwall rocks of the Ca\u00f1ada David detachment fault, northeastern Baja California, record late Eocene-earliest Oligocene and late Neogene cooling events previously unrecognized in the region. Biotite ^(40)Ar/^(39)Ar ages of \u223c65 Ma reflect slow cooling through \u223c350\u00b0C, 5 to 10 m.y. later than is typical in the region. Multiple diffusion domain modeling of K feldspar ^(40)Ar/^(39)Ar release spectra shows very slow cooling (\u223c1\u00b0C/m.y.) from \u223c65 to \u223c45 Ma. Accelerated cooling from \u223c315\u00b0C to \u223c215\u00b0C between \u223c45 and \u223c33 Ma records at least 3\u20134 km of denudation that we relate to east-side-up reactivation of late Cretaceous structures that generally follow the oceanic-continental suture. Previously established rivers flowing west from mainland Mexico apparently became further entrenched during this uplift and continued to supply distinctive rhyolitic detritus to the coast. Ultimately, surface uplift disrupted and rerouted the extraregional rivers some 2 to 6 m.y. before the cooling event ended. Footwall rocks remained nearly isothermal from \u223c30 to \u223c15\u201310 Ma, when renewed rapid cooling (33\u00b0 \u00b1 17\u00b0C/m.y.) began in response to footwall exhumation by top-to-the-west low-angle normal faulting that accommodated rift-related extension in what finally became the Gulf of California. Apatite fission track and (U-Th)/He ages of \u223c5 Ma and \u223c4 Ma, respectively, record final detachment-related cooling through \u223c110\u00b0C to \u223c70\u00b0C. Thermal-kinematic modeling suggests that 5\u20137 km of late Neogene tectonic denudation and 10\u201312 km of horizontal extension were necessary in order to unroof the samples by 2 Ma. Additional extension, of unknown magnitude, has probably occurred subsequently. Geodetically measured horizontal extension rates are considerably higher than the long-term extension rate that can be attributed to detachment faulting.", "date": "2000-04", "date_type": "published", "publication": "Tectonics", "volume": "19", "number": "2", "publisher": "American Geophysical Union", "pagerange": "197-212", "id_number": "CaltechAUTHORS:20121128-155419476", "issn": "0278-7407", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121128-155419476", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "UC MEXUS" }, { "agency": "UCLA Committee on Research" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-FG-03-89ER14049" }, { "agency": "CONACYT", "grant_number": "4345-PT" }, { "agency": "Stanford University McGee grant" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/1999TC001123", "primary_object": { "basename": "1999TC001123.pdf", "url": "https://authors.library.caltech.edu/records/1rj97-m8x95/files/1999TC001123.pdf" }, "resource_type": "article", "pub_year": "2000", "author_list": "Axen, Gary J.; Grove, Marty; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/eedsz-0k495", "eprint_id": 37451, "eprint_status": "archive", "datestamp": "2023-08-22 00:56:29", "lastmod": "2023-10-23 17:28:45", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Helium diffusion from apatite: General behavior as illustrated by Durango fluorapatite", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2000 American Geophysical Union.\n\nManuscript Accepted: 30 September 1999; Manuscript Received: 29 June 1999.\n\nI wish to thank G. Rossman for extensive discussions of apatite mineralogy and for assisting with the DTA and TG measurements, and L. Hedges for sample preparation. This work was supported by the National Science Foundation.\n\nPublished - 1999JB900348.pdf
", "abstract": "High-precision stepped-heating experiments were performed to better characterize helium diffusion from apatite using Durango fluorapatite as a model system. At temperatures below 265\u00b0C, helium diffusion from this apatite is a simple, thermally activated process that is independent of the cumulative fraction of helium released and also of the heating schedule used. Across a factor of \u223c4 in grain size, helium diffusivity scales with the inverse square of grain radius, implying that the physical grain is the diffusion domain. Measurements on crystallographically oriented thick sections indicate that helium diffusivity in Durango apatite is nearly isotropic. The best estimate of the activation energy for He diffusion from this apatite is E_a = 33\u00b10.5 kcal/mol, with log(D_0) = 1.5\u00b10.6 cm^2/s. The implied He closure temperature for a grain of 100 \u03bcm radius is 68\u00b0C assuming a 10\u00b0C/Myr cooling rate; this figure varies by \u00b15\u00b0C for grains ranging from 50 to 150 \u03bcm radius. When this apatite is heated to temperatures from 265 to 400\u00b0C, a progressive and irreversible change in He diffusion behavior occurs: Both the activation energy and frequency factor are reduced. This transition in behavior coincides closely with progressive annealing of radiation damage in Durango apatite, suggesting that defects and defect annealing play a role in the diffusivity of helium through apatite.", "date": "2000-02-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "105", "number": "B2", "publisher": "American Geophysical Union", "pagerange": "2903-2914", "id_number": "CaltechAUTHORS:20130311-150217210", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130311-150217210", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/1999JB900348", "primary_object": { "basename": "1999JB900348.pdf", "url": "https://authors.library.caltech.edu/records/eedsz-0k495/files/1999JB900348.pdf" }, "resource_type": "article", "pub_year": "2000", "author_list": "Farley, K. A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/m67zg-hsj57", "eprint_id": 11486, "eprint_status": "archive", "datestamp": "2023-08-21 20:52:36", "lastmod": "2023-10-16 23:49:22", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "J. M." } }, { "id": "Crawford-A", "name": { "family": "Crawford", "given": "Anthony" } }, { "id": "Elliott-T", "name": { "family": "Elliott", "given": "Tim" } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Valley-J-W", "name": { "family": "Valley", "given": "John W." } }, { "id": "Stolper-E-M", "name": { "family": "Stolper", "given": "Edward M." }, "orcid": "0000-0001-8008-8804" } ] }, "title": "Oxygen isotope geochemistry of oceanic-arc lava", "ispublished": "pub", "full_text_status": "public", "keywords": "oxygen isotopes; arc volcanism", "note": "\u00a9 Oxford University Press 2000. Reprinted with permission. \n\nReceived November 2, 1998; Revised typescript accepted July 15, 1999. \n\nWe thank Bob Stern for his gracious supply of samples and unpublished data for shoshonites from the Mariana arc. Glen Gaetani, Mike Baker, Ronit Kessel, Peter Wyllie, Bob Stern, and Terry Plank improved upon this work through informal reviews of an early draft of this manuscript and/or helpful discussions on subjects related to this work. We thank Jean Morrison for allowing us to use her laboratory facilities at USC, and Mike Spicuzza and Nami Kitchen for laboratory assistance at the UW and at USC, respectively. A portion of the data presented in this manuscript was collected by Ronit Kessel as part of her graduate studies at Caltech. We gratefully acknowledge the improvements to this manuscript resulting from reviews by Chris Hawkesworth, Peter Kelemen, and Colin Macpherson. This work was supported by NSF Grant EAR-9805101. This is Contribution 8556 of the Division of Geological and Planetary Sciences at the California Institute of Technology.\n\nPublished - EILjpet00.pdf
", "abstract": "Variations of oxygen isotope ratios in arc-related lavas can constrain the contributions of subducted crustal igneous rocks, sediments, and fluids to the sub-arc mantle. We have measured oxygen isotope ratios in 72 arc and back-arc lavas from five ocean\u2013ocean subduction zone systems using laser-fluorination analyses of olivine and other phenocrysts and glass. Eighty percent of our samples have {delta}18O values for any given phase (olivine, plagioclase, glass, or biotite) within 0\u00b72{per thousand} of the average value for that phase in upper-mantle peridotites and mid-ocean ridge basalt (MORB); the range for each phase is <=1\u00b70{per thousand}. This result contrasts with previous studies of whole-rock samples (which are significantly more variable even after exclusion of samples believed to be altered or fractionated by magmatic differentiation) and demonstrates that most arc-related lavas contain <=1\u20132% of 18O-enriched crustal oxygen from any source (i.e. assimilation or subducted contributions). Elevations in {delta}18O that do occur in these basic, arc-derived magmas relative to values most common for mantle-derived lavas are associated both with 'enriched' radiogenic isotope signatures and, even more strongly, with chemical indices consistent with high integrated extents of melting of their peridotite sources. We interpret these relationships as evidence that melting in the sources of the high-{delta}18O lavas we have studied was fluxed by addition of high-{delta}18O aqueous fluid (or perhaps a hydrous melt) from the subducted slab, such that sources that contain relatively large components of slab-derived fluid or melt are both relatively 18O enriched and also experienced relatively large amounts of melting. We have developed a quantitative model linking the amount of melting to the extents of 18O, radiogenic isotope, and trace-element enrichment in a mantle source being fluxed by addition of aqueous fluid. Comparison of this model with observed variations in the geochemistry of lavas from the Vanuatu\u2013Fiji\u2013New Caledonia region (the suite of related samples showing the greatest range in {delta}18O observed in this study) constrains the amounts and chemical and isotopic compositions of slab-derived phases in the sources of these arc-related lavas. Assuming a {delta}18O value of 20{per thousand} for the slab-derived fluid, 0\u00b75\u20131\u00b70 wt % is added to the sources of most mantle-derived arc magmas; the maximum amount of slab-derived flux in the sources of arc magmas according to our results is 2\u00b75 wt %.", "date": "2000-02", "date_type": "published", "publication": "Journal of Petrology", "volume": "41", "number": "2", "publisher": "Oxford University Press", "pagerange": "229-256", "id_number": "CaltechAUTHORS:EILjpet00", "issn": "0022-3530", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:EILjpet00", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9805101" } ] }, "other_numbering_system": { "items": [ { "id": "8556", "name": "Caltech Division of Geological and Planetary Sciences Contribution" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/petrology/41.2.229", "primary_object": { "basename": "EILjpet00.pdf", "url": "https://authors.library.caltech.edu/records/m67zg-hsj57/files/EILjpet00.pdf" }, "resource_type": "article", "pub_year": "2000", "author_list": "Eiler, J. M.; Crawford, Anthony; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/5zrpq-5eb71", "eprint_id": 35588, "eprint_status": "archive", "datestamp": "2023-08-22 14:07:20", "lastmod": "2023-10-20 19:11:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Reiners-P-W", "name": { "family": "Reiners", "given": "Peter W." }, "orcid": "0000-0001-7240-2373" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Helium diffusion and (U\u2013Th)/He thermochronometry of titanite", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1999 Elsevier Science Ltd. Received December 14, 1998; accepted in revised form April 21, 1999. We thank Martha House for providing us with MH96\u20136 titanite, Barry Kohn for the Arkaroola, FCT, and MD samples, and Matt Heizler for the MH-10 and 42 samples. Thanks also to Lindsey Hedges, Sujoy Mukhopadyay, and Martha House for valuable help and advice in the lab, Mark Garcia for preparing the Gold Butte\nsamples, Paul Carpenter for electron microprobe assistance, and Anna Johansen, Tatiana Piatina, Penny Kneebone, and Yaniv Dubowski for ICP-MS advice. We appreciate constructive reviews from Frank Richter and an anonymous reviewer. This work was funded by a Caltech Texaco Postdoctoral Fellowship to Peter Reiners and by a Packard\nFellowship and an NSF grant to Ken Farley.", "abstract": "We have explored the diffusivity characteristics of radiogenic He in titanite (sphene) and have developed analytical techniques for (U\u2013Th)/He dating of this mineral. Results of incremental He outgassing experiments performed on titanites from a variety of geological environments suggest a thermally activated volume diffusion mechanism with an activation energy of 44.6 \u00b1 3.4 (2\u03c3) kcal/mol and a frequency factor of \u223c60 cm^2/s. Diffusivity is highly linearly correlated with the inverse square of the grain size, indicating that the He diffusion domain in titanite is the crystal itself. For typical titanite grains of 200- to 800-\u03bcm minimum dimension, the He closure temperature is in the range 191 to 218\u00b0C (for a cooling rate of 10\u00b0C/Myr). There is no indication in the titanites we studied that radiation damage plays a major role in He diffusion. (U\u2013Th)/He ages of titanites from quickly cooled rocks yield ages (with \u223c5\u20138% 1\u03c3 reproducibility) that are concordant with known ages, and (U-Th)/He ages of titanites from slowly cooled rocks are consistent with independently established cooling paths, supporting the closure temperature estimates. These experiments suggest that titanite (U\u2013Th)/He ages may be useful for constraining cooling histories at temperatures near the lower limit of those accessed by feldspar ^(40)Ar/^(39)Ar dating but higher than apatite fission track or (U-Th)/He dating.", "date": "1999-11", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "63", "number": "22", "publisher": "Elsevier", "pagerange": "3845-3859", "id_number": "CaltechAUTHORS:20121120-151948085", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-151948085", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Texaco Postdoctoral Fellowship" }, { "agency": "Packard Fellowship" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0016-7037(99)00170-2", "resource_type": "article", "pub_year": "1999", "author_list": "Reiners, Peter W. and Farley, Kenneth A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/r0e3c-5bv09", "eprint_id": 36687, "eprint_status": "archive", "datestamp": "2023-08-22 13:59:35", "lastmod": "2023-10-20 23:29:41", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "McInnes-B-I-A", "name": { "family": "McInnes", "given": "Brent I. A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Sillitoe-R-H", "name": { "family": "Sillitoe", "given": "Richard H." } }, { "id": "Kohn-B-P", "name": { "family": "Kohn", "given": "Barry P." } } ] }, "title": "Application of apatite (U-Th)/He thermochronometry to the determination of the sense and amount of vertical fault displacement at the Chuquicamata porphyry copper deposit, Chile", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1999 Society of Economic Geologists. June 29, 1998; February 24, 1999. This study was supported jointly by CODELCO-Chile and the Department of Industry, Science and Tourism Australia-USA Bilateral Science and Technology Collaboration program. KAF acknowledges funds from a David\nand Lucille Packard Foundation Fellowship Francisco Camus approved the study on behalf of CODELCO-Chile and facilitated the participation of RHS. Guillermo Ossand\u03ccn provided valuable background information regarding previous geochronologic and structural studies in the region. Roberto Fr\u00e9raut assisted in the collection of assessment samples during an initial visit to Chuquicamata, and Irene Aracena participated in the main sampling program. BIAM is grateful to Noel White and BHP Minerals for supporting his participation on a field trip to the study area in 1995. Chris Ryan is thanked for producing the PIXE trace element maps of apatite High-quality mineral separates were provided by Jeff Davis. Irradiation costs for fission-track work were met through a grant from the Australian Institute\nof Nuclear Science and Engineering. This study was partly financed by the Australian Research Council and the Australian Geodynamic Cooperative Research Centre, and this paper is published with the permission of the Director, Australian Geodynamics Cooperative Research Centre. Comments on earlier drafts by Jorge Skarmeta Fracisco Camus, Andy Tomlinson, Noreen Evans, and Kai Yang led to significant improvements. We thank Andrew Warnock for a helpful review.", "abstract": "Chuquicamata is the world's largest porphyry copper deposit, notwithstanding the fact that a portion of the orebody has been faulted off by postmineralization movement along the West fault. In order to locate the missing portion of the orebody in the vertical dimension, a study was designed to estimate the sense and amount of vertical displacement along this major structure by measuring the (U-Th)/He and fission-track ages of vertically distributed apatite samples from each of the crustal blocks (Fortuna and Chuquicamata Intrusive Complexes) bordering the fault. Apatite (U-Th)/He ages range from 32 to 16 Ma, whereas apatite fission-track ages range from 33 to 28 Ma, reflecting the lower closure temperature of the (U-Th)/He thermochronology method ( approximately 75 degrees vs. approximately 125 degrees C for cooling rates of approximately 10 degrees C/m.y.). The (U-Th)/He ages decrease systematically with depth in both blocks, however, the age-elevation curve for the western Fortuna block is shifted vertically with respect to the eastern Chuquicamata block, indicating that the postmineralization denudation was significantly greater to the west. The minimum vertical displacement along the West fault is estimated to be 600 + or - 100 m, implying that the missing portion of the Chuquicamata deposit should be located at a present-day elevation of at least 3,600 m. The new apatite ages, combined with previous thermochronometric data (Rb-Sr, U-Pb, Ar-Ar), reveal rapid cooling rates ( approximately 100 degrees C/m.y.) for the Chuquicamata deposit following emplacement at about 35 Ma, thereby indicating that the Cu mineralization took place at a depth of less than 4 km.", "date": "1999-09", "date_type": "published", "publication": "Economic Geology", "volume": "94", "number": "6", "publisher": "Society of Economic Geologists", "pagerange": "937-947", "id_number": "CaltechAUTHORS:20130130-105254249", "issn": "0361-0128", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130130-105254249", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "CODELCO-Chile" }, { "agency": "Department of Industry Science and Tourism Australia-USA Bilateral Science and Technology program" }, { "agency": "David and Lucile Packard Foundation Fellowship" }, { "agency": "Australian Institute of Nuclear Science and Engineering (AINSE)" }, { "agency": "Australian Research Council" }, { "agency": "Australian Geodynamic Cooperative Research Centre" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.2113/gsecongeo.94.6.937", "resource_type": "article", "pub_year": "1999", "author_list": "McInnes, Brent I. A.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/dn69r-dht70", "eprint_id": 35543, "eprint_status": "archive", "datestamp": "2023-08-22 13:54:39", "lastmod": "2023-10-20 19:07:23", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "House-M-A", "name": { "family": "House", "given": "Martha A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Kohn-B-P", "name": { "family": "Kohn", "given": "Barry P." } } ] }, "title": "An empirical test of helium diffusion in apatite: borehole data from the Otway basin, Australia", "ispublished": "pub", "full_text_status": "restricted", "keywords": "helium; age; apatite; diffusivity; Otway Basin", "note": "\u00a9 1999 Elsevier Science B.V. Received 26 June 1998; accepted 5 May 1999. Acknowledgement is made to the Donors of the Petroleum Research Fund, administered by the\nAmerican Chemical Society, for support of this research\n(M.A.H.) and grants from the National Science Foundation (K.A.F.). Lindsey Hedges of the Noble Gas Laboratory at Caltech provided analytical assistance. Ken Wilson, Bob Harms and Kathy Hill of Petroleum Division of the Victorian Department of Natural Resources and Environment greatly facilitated the examination of the Otway basin well\nreports studied and the collection of core samples.\nComments by C.W. Naeser and two anonymous reviewers\nand editorial assistance from M. Kastner greatly improved the manuscript. Part of this study was conducted as part of the Australian Geodynamic Cooperative Research Centre and this paper is published with the permission of the Director, AGCRC. [MK]", "abstract": "We have analyzed helium ages of apatites from several boreholes in the Otway basin, Australia, to evaluate whether laboratory helium diffusivity can be accurately extrapolated to conditions relevant in nature. Downhole apatite helium ages define a broad swath of values from 78\u201371 Ma at the surface (15\u00b0C) to nearly zero at depths corresponding to ambient temperatures of \u223c80\u00b0C. The width of the swath results from uncertainties in corrected borehole temperatures, differences in the thermal history experienced by the various boreholes, and possibly from slightly different helium diffusivities among the detrital apatite grains studied. In the eastern Otway basin, the shape and position of the helium age profile is in good agreement with predictions based on the extrapolation of laboratory diffusivity data for Durango apatite coupled with published thermal histories for this part of the basin. In contrast, helium ages are much younger than predicted in the western Otway basin. Based on measured ages from Otway sediments, which have been essentially isothermal over the last few million years, an empirical diffusivity (D/\u03b1^2) of 2\u00d710^(\u221215) s^(\u22121) can be assigned to apatites residing at downhole temperatures of 67\u201397\u00b0C. This empirical diffusivity is consistent with laboratory diffusion measurements, demonstrating that such measurements are reasonably accurate and can be applied with confidence to natural geologic settings. Given this confirmation of the laboratory diffusivity data, the discrepancy between the observed and modeled helium age profiles in the western Otway basin suggests that these sediments recently experienced higher temperatures than presently supposed.", "date": "1999-07-30", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "170", "number": "4", "publisher": "Elsevier", "pagerange": "463-474", "id_number": "CaltechAUTHORS:20121119-112755758", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121119-112755758", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "American Chemical Society Petroleum Research Fund" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(99)00120-X", "resource_type": "article", "pub_year": "1999", "author_list": "House, Martha A.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ssmyr-pz253", "eprint_id": 116371, "eprint_status": "archive", "datestamp": "2023-08-22 13:47:22", "lastmod": "2023-10-24 21:06:21", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Reiners-Peter-W", "name": { "family": "Reiners", "given": "Peter W." }, "orcid": "0000-0001-7240-2373" }, { "id": "Nenow-Victor", "name": { "family": "Nenow", "given": "Victor" } } ] }, "title": "An Apparatus for High-Precision Helium Diffusion Measurements from Minerals", "ispublished": "pub", "full_text_status": "public", "keywords": "Analytical Chemistry", "note": "We thank P. Zeitler and P. Copeland for thoughtful reviews\nand the David and Lucille Packard Foundation and the National\nScience Foundation for supporting this work.", "abstract": "We describe a simple and low-cost apparatus for in-vacuum helium diffusion measurements that reduces temperature gradients, set point overshoot, and ramping times compared with conventional resistance furnace techniques. The sample, suspended by a thin wire in a vacuum chamber, is heated by radiation from an Al-coated projector bulb passed through a sapphire viewport. Because the total mass of the sample package being heated is small (typically <100 mg), thermal gradients and thermal inertia are both small. In experiments with set points between 100 and 750 \u00b0C, this apparatus can achieve set point from room temperature in \u223c90 s, usually with <3 \u00b0C of set point overshoot persisting for just a few seconds. Helium diffusion coefficient measurements indirectly indicate that temperatures are precise and reproducible to better than \u00b12 \u00b0C.", "date": "1999-05-15", "date_type": "published", "publication": "Analytical Chemistry", "volume": "71", "number": "10", "publisher": "American Chemical Society", "pagerange": "2059-2061", "id_number": "CaltechAUTHORS:20220822-171697000", "issn": "0003-2700", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220822-171697000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "David and Lucile Packard Foundation" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1021/ac9813078", "resource_type": "article", "pub_year": "1999", "author_list": "Farley, Kenneth A.; Reiners, Peter W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/b1z0a-js913", "eprint_id": 35587, "eprint_status": "archive", "datestamp": "2023-08-22 13:36:06", "lastmod": "2023-10-20 19:11:32", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Patterson-D-B", "name": { "family": "Patterson", "given": "D. B." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Norman-M-D", "name": { "family": "Norman", "given": "M. D." } } ] }, "title": "^4He as a tracer of continental dust: A 1.9 million year record of aeolian flux to the west equatorial Pacific Ocean", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1999 Elsevier Science Ltd. Received June 10, 1998; accepted in revised form November 18, 1998. This work was supported by the David and Lucille Packard Foundation and the Australian Research Council. We thank Dr. David Rea and two anonymous referees for their comments. Special thanks to Dr. R. Muller for providing the Fourier Transform\nspectral analysis. DBP wishes to also thank Mr. John Miller of ODP for help and hospitality during sample retrieval. This is GEMOC Contribution 142.", "abstract": "The mass accumulation rates (MARs) of aeolian dust in the ocean basins provide an important record of climate in the continental source regions of atmospheric dust and of the prevailing wind patterns responsible for dust transport in the geologic past. The incorporation of other terrigenous components such as volcanic ashes in seafloor sediments, however, often obscures the aeolian dust record. We describe a new approach which uses the delivery rate of crustal ^4He to seafloor sediments as a proxy for the mass accumulation rate of old continental dust which is unaffected by the addition of other terrigenous components.\nWe have determined the flux of crustal ^4He delivered to the seafloor of the Ontong Java Plateau (OJP) in the western equatorial Pacific over the last 1.9 Myrs. Crustal ^4He fluxes vary between 7.7 and 30 ncc cm^(\u22122) kyr^(\u22121) and show excellent correlation with global climate as recorded by oxygen isotopes, with high crustal ^4He fluxes associated with glacial periods over the entire interval studied. Furthermore, the onset of strong 100 kyr glacial\u2013interglacial climate cycling is clearly seen in the ^4He flux record about 700 kyrs ago. These data record variations in the supply of Asian dust in response to climate driven changes in the aridity of the Asian dust sources, consistent with earlier work on Asian dust flux to the northern Pacific Ocean. However, in contrast to previous studies of sites in the central and eastern equatorial Pacific Ocean, there is no evidence that the Inter Tropical Convergence Zone (an effective rainfall barrier to the southward transport of northern hemisphere dust across the equator in the central and eastern Pacific) has influenced the delivery of Asian dust to the OJP.\nThe most likely carrier phase for crustal helium in these sediments is zircon, which can reasonably account for all the ^4He observed in the samples. As a first order estimate, these results suggest that the mass accumulation rate of Asian dust on the OJP over the last 1.9 Myrs varied from about 4 to 15 mg cm^(\u22122) kyr^(\u22121). In contrast, previous studies show that over the same interval the total MAR of terrigenous dust (i.e. Asian dust plus local volcanics) on OJP varied between about 34 and 90 mg cm^(\u22122) kyr^(\u22121).", "date": "1999-03", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "63", "number": "5", "publisher": "Elsevier", "pagerange": "615-625", "id_number": "CaltechAUTHORS:20121120-150916146", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-150916146", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "David and Lucile Packard Foundation" }, { "agency": "Australian Research Council" } ] }, "other_numbering_system": { "items": [ { "id": "142", "name": "GEMOC" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0016-7037(99)00077-0", "resource_type": "article", "pub_year": "1999", "author_list": "Patterson, D. B.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/jw2cq-tf096", "eprint_id": 35586, "eprint_status": "archive", "datestamp": "2023-08-22 13:18:43", "lastmod": "2023-10-20 19:11:26", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Patterson-D-B", "name": { "family": "Patterson", "given": "D. B." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Extraterrestrial ^3He in seafloor sediments: Evidence for correlated 100 kyr periodicity in the accretion rate of interplanetary dust, orbital parameters, and Quaternary climate", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1998 Elsevier Science Ltd. Received November 13, 1997; accepted in revised form August 20, 1998. This work was supported by NASA and the David and Lucille Packard Foundation. We thank R. Muller and F. Marcantonio for detailed reviews, and Stan Love for fruitful discussions. DBP wishes to also thank John Miller of ODP for help and hospitality during sample retrieval. The Fourier transform data was generously provided by R. Muller, and we thank S. Kortenkamp for providing the results of the IDP capture rate calculations.", "abstract": "We have determined the helium abundance and isotopic composition of seafloor carbonate sediments from the flanks of the Ontong Java Plateau, western equatorial Pacific Ocean (ODP Site 806). These results provide a two million year record of the burial flux of extraterrestrial ^3He, which we believe is a proxy for the terrestrial accretion rate of interplanetary dust particles. The ^3He burial flux prior to \u223c700 ka was relatively low, \u223c0.5 pcc cm^(\u22122) kyr^(\u22121), but from 700 ka to the present, the burial flux gradually increased to a value of \u223c1.0 pcc cm^(\u22122) kyr^(\u22121). 100 kyr periodicity in the ^3He burial flux is apparent over the last 700 kyr and correlates with the oxygen isotope record of global climate, with high ^3He burial fluxes associated with interglacial periods. This periodicity and phase are consistent with previous ^3He measurements in North Atlantic sediments. Although 100 kyr periodicity in ^3He burial flux is in agreement with recent predictions of the accretion rate of interplanetary dust based on a model of the orbital evolution of asteroidal debris, the measurements and predictions differ by one half cycle in phase. Nevertheless, our observations suggest the terrestrial accretion rate of interplanetary dust is controlled by orbital eccentricity and/or inclination relative to the solar-system invariable plane. Such control is a necessary but not sufficient condition for the hypothesis of Muller and MacDonald (1995) that variations in extraterrestrial dust accretion modulates terrestrial climate with a 100 kyr period.\nWe also identify several brief (<25 kyr) intervals of strongly enhanced ^3He burial, possibly related to random and transient fluctuations in the accretion rate of asteroidal or cometary dust particles.", "date": "1998-12", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "62", "number": "23-24", "publisher": "Elsevier", "pagerange": "3669-3682", "id_number": "CaltechAUTHORS:20121120-145940332", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-145940332", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" }, { "agency": "David and Lucile Packard Foundation" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0016-7037(98)00263-4", "resource_type": "article", "pub_year": "1998", "author_list": "Patterson, D. B. and Farley, K. A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/zd0de-0v868", "eprint_id": 37969, "eprint_status": "archive", "datestamp": "2023-08-22 13:16:44", "lastmod": "2023-10-23 19:36:46", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "House-M-A", "name": { "family": "House", "given": "Martha A." } }, { "id": "Wernicke-B-P", "name": { "family": "Wernicke", "given": "Brian P." }, "orcid": "0000-0002-7659-8358" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Dating topography of the Sierra Nevada, California, using apatite (U\u2013Th)/He ages", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1998 Macmillan Publishers Ltd.\n\nReceived 10 December 1997; accepted 27 July 1998.\n\nThis work is part of the Southern Sierra Nevada Continental Dynamics Project,\nsupported by NSF's Continental Dynamics Program. We thank M. Ducea and J. Saleeby for permission to\ndiscuss their results before publication.\n\nSupplemental Material - 396066A0.house.doc
", "abstract": "The upward motion of rock masses relative to the Earth's surface has been documented for most of the main mountain belts using thermochronological and petrological techniques. More fundamental to the physical processes of mountain building, however, is the motion of the Earth's surface itself, which remains elusive. Here we describe a technique for estimating the age of topographic relief by mapping the low-temperature thermal structure imparted by river incision using the ages of apatites determined from their uranium, thorium and helium contents. The technique exploits horizontal variations in temperature in the shallow crust that result from range-normal river drainages, because cooling beneath ancient river valleys occurs earlier than beneath intervening ridges. Our results from the Sierra Nevada, California, indicate that two of the modern transverse drainages, the Kings and the San Joaquin, had developed deep canyons by the Late Cretaceous period, suggesting that the high topography of the range is ~50\u201360 million years older than generally thought.", "date": "1998-11-05", "date_type": "published", "publication": "Nature", "volume": "396", "number": "6706", "publisher": "Nature Publishing Group", "pagerange": "66-69", "id_number": "CaltechAUTHORS:20130416-111249596", "issn": "0028-0836", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130416-111249596", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/23926", "primary_object": { "basename": "396066A0.house.doc", "url": "https://authors.library.caltech.edu/records/zd0de-0v868/files/396066A0.house.doc" }, "resource_type": "article", "pub_year": "1998", "author_list": "House, Martha A.; Wernicke, Brian P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/pd1js-vbc50", "eprint_id": 35560, "eprint_status": "archive", "datestamp": "2023-08-22 13:14:43", "lastmod": "2023-10-20 19:08:33", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Patterson-D-B", "name": { "family": "Patterson", "given": "D. B." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Schmitz-B", "name": { "family": "Schmitz", "given": "B." } } ] }, "title": "Preservation of extraterrestrial ^3He in 480-Ma-old marine limestones", "ispublished": "pub", "full_text_status": "restricted", "keywords": "He-3; isotopes; Ordovician; Sweden; meteorites", "note": "\u00a9 1998 Elsevier Science B.V. Received 2 March 1998; revised version received 20 August 1998; accepted 24 August 1998. This work was supported by the David and Lucille Packard Foundation and NASA. We thank Dr. C. Koeberl, Dr. D. Hilton, and an anonymous reviewer for thoughtful and constructive comments. We also thank Dr. M. Tassinari for providing the meteorite samples. [MK]", "abstract": "We have measured the helium abundance and isotopic composition of a suite of Lower Ordovician marine limestones and associated fossil meteorites from Kinnekulle, Sweden. Limestone ^3He/^4He ratios as high as 11.5 times the atmospheric value in fused samples and up to 23 times atmospheric in a single step-heat fraction indicate the presence of extraterrestrial helium, and demonstrate that at least a fraction of the extraterrestrial ^3He carried by interplanetary dust particles must be retained against diffusive and diagenetic losses for up to 480 Ma. The carrier phase has not been identified but is not magnetic. Extrapolation of high-temperature ^3He diffusivities in these sediments is consistent with strong retention of extraterrestrial ^3He under ambient Earth-surface conditions. Combination of the observed helium concentrations with sedimentation rates estimated from conodont biostratigraphy suggest that the flux of extraterrestrial ^3He in the Early Ordovician was about 0.5\u00d710^(\u221212) cm^3 STP cm^(\u22122) ka^(\u22121), ignoring potential post-deposition helium loss. This value is indistinguishable from the average ^3He flux estimated for the Cenozoic Era. In contrast, previous studies of fossil meteorites, Ir abundances, and Os isotopic ratios in the limestone suggest that the total accretion rate of extraterrestrial material during the studied interval was at least an order of magnitude higher than the Cenozoic average. This disparity may reflect significant post-depositional loss of ^3He from IDPs within these old limestones; if so, the match between the Ordovician flux and the Cenozoic average would be fortuitous. Alternatively, the size distribution of infalling objects during the Early Ordovician may have been enriched only in extraterrestrial material too large to retain ^3He during atmospheric entry heating (>\u223c30 \u03bcm). The fossil meteorites themselves also preserve extraterrestrial helium. Meteorite 3He concentrations of 2 to 9\u00d710^(\u221212) cm^3 STP g^(\u22121) are several orders of magnitude lower than found in most modern meteorites, suggesting very substantial helium loss (probably >99.9%) from these chemically altered objects. The meteorites carry ^3He concentrations only a factor of a few higher than the host limestones. The meteorites themselves cannot be the source of the extraterrestrial ^3He observed in the limestones.", "date": "1998-11", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "163", "number": "1-4", "publisher": "Elsevier", "pagerange": "315-325", "id_number": "CaltechAUTHORS:20121120-101104468", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-101104468", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "David and Lucile Packard Foundation" }, { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(98)00197-6", "resource_type": "article", "pub_year": "1998", "author_list": "Patterson, D. B.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/q3wem-qqj30", "eprint_id": 35575, "eprint_status": "archive", "datestamp": "2023-08-22 12:55:56", "lastmod": "2023-10-20 19:10:19", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wolf-R-A", "name": { "family": "Wolf", "given": "R. A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Kass-D-M", "name": { "family": "Kass", "given": "D. M." } } ] }, "title": "Modeling of the temperature sensitivity of the apatite (U\u2013Th)/He thermochronometer", "ispublished": "pub", "full_text_status": "public", "keywords": "Apatite; He; Dating; Modeling", "note": "\u00a9 1998 Elsevier Science B.V. \n\nReceived 13 August 1997; accepted 30 January 1998. \n\nThis work was supported by the U.S. National Science Foundation. We thank G. Wagner for a helpful review.\n\nSubmitted - A_Sensitivity_Analysis_of_the_Apatite.pdf
", "abstract": "Apatite (U\u2013Th)/He apparent ages will generally reflect residence for extended periods at temperatures where helium is neither quantitatively retained nor lost by diffusion. To characterize the response of apatite He ages to thermal histories involving partial He retention, we explored solutions to the He production\u2013diffusion equation. Under thermally static conditions, the analytical solution to this equation, coupled with published diffusivity data, demonstrates that the zone of partial He retention extends from about \u223c40\u00b0C to \u223c85\u00b0C. This zone lies at temperatures \u223c35\u00b0C cooler than the analogous fission track partial annealing zone. He ages within the partial retention zone ultimately achieve a balance between He production and loss, yielding a steady state age. Both the ultimate age and the time it takes to achieve this age are temperature dependent. For example, an apatite held at 75\u00b0C equilibrates to an age of \u223c2 Ma after \u223c17 Myr, regardless of whether equilibrium is approached from a higher or a lower initial He age. For representative dynamic thermal histories, we evaluated apatite He ages using a numerical solution to the ingrowth\u2013diffusion equation. The results illustrate the sensitivity of He ages to various geologic histories and are useful for understanding He age\u2013elevation relationships and for testing time\u2013temperature paths derived from apatite fission track length distributions. In addition, although He diffuses rapidly from apatite at shallow crustal temperatures, modeling of ambient temperature fluctuations indicates that He ages are nearly unaffected by surficial processes.", "date": "1998-06-05", "date_type": "published", "publication": "Chemical Geology", "volume": "148", "number": "1-2", "publisher": "Elsevier", "pagerange": "105-114", "id_number": "CaltechAUTHORS:20121120-132902967", "issn": "0009-2541", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-132902967", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0009-2541(98)00024-2", "primary_object": { "basename": "A_Sensitivity_Analysis_of_the_Apatite.pdf", "url": "https://authors.library.caltech.edu/records/q3wem-qqj30/files/A_Sensitivity_Analysis_of_the_Apatite.pdf" }, "resource_type": "article", "pub_year": "1998", "author_list": "Wolf, R. A.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/tyjx8-4cn21", "eprint_id": 33479, "eprint_status": "archive", "datestamp": "2023-08-22 12:53:53", "lastmod": "2023-10-18 20:04:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "John M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Stolper-E-M", "name": { "family": "Stolper", "given": "Edward M." }, "orcid": "0000-0001-8008-8804" } ] }, "title": "Correlated helium and lead isotope variations in Hawaiian lavas", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1998 Elsevier Science Ltd. \n\nReceived 7 July 1997. Revised 13 February 1998. Accepted 13 February 1998. Available online 25 May 2000. \n\nWe thank Don Porcelli and Don Anderson for the insights they provided in discussion of this work. This paper was improved by helpful and detailed reviews by Mark Kurz and an anonymous reviewer. This work was funded by NSF grant EAR-9628142 to KAF and EMS and DOE grant DEFG03-85ER13445 to EMS.", "abstract": "Variations in ^3He/^4He ratios among Hawaiian shield-building and pre-shield basalts are correlated with variations in ^(208)Pb/^(204)Pb and ^(206)Pb/^(204)Pb ratios. Using this correlation, the ^3He/^4He ratio of Hawaiian lavas can be predicted to within 2.9 R_A (mean deviation) between 7 and 32 R_A based only upon the lead isotope composition. This level of prediction is as good as can be expected based upon the precision of lead isotope ratio measurements. This correlation demonstrates a coupling of volatile and nonvolatile elements in the sources of Hawaiian basalts and allows the nonvolatile-element characteristics of the high-^3He/^4He component of the mantle sources of Hawaiian lavas to be defined. This result confirms and extends previous inferences based upon correlations between helium and strontium isotope ratios in individual suites of Hawaiian lavas. The source of high ^3He/^4He ratios in Hawaiian lavas has a higher time-integrated Th/U ratio than the sources of Pacific mid-ocean ridge basalts, consistent with it being a mixture containing primitive mantle or having differentiated in two or more stages from primitive mantle.", "date": "1998-06", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "62", "number": "11", "publisher": "Elsevier", "pagerange": "1977-1984", "id_number": "CaltechAUTHORS:20120823-103942125", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120823-103942125", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9628142" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-FG03-85ER13445" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0016-7037(98)00113-6", "resource_type": "article", "pub_year": "1998", "author_list": "Eiler, John M.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/k8wtb-hdb72", "eprint_id": 35607, "eprint_status": "archive", "datestamp": "2023-08-22 12:54:10", "lastmod": "2023-10-20 19:12:54", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Spotila-J-A", "name": { "family": "Spotila", "given": "James A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Sieh-K-E", "name": { "family": "Sieh", "given": "Kerry" }, "orcid": "0000-0002-7311-2447" } ] }, "title": "Uplift and erosion of the San Bernardino Mountains associated with transpression along the San Andreas fault, California, as constrained by radiogenic helium thermochronometry", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1998 American Geophysical Union. Received July 22, 1997;\nrevised January 29, 1998; accepted February 2, 1998. We thank Martha House and Rich Wolf\nfor significant help with lab work, Doug Yule for help with\nsample collection, and Martha, Rich, Doug, Andrew Meigs,\nand Lee Silver for valuable help with interpretations and\nregional geology. We also thank Robert Castle and Peter\nSadler for helpful reviews of this manuscript. This project was\nfunded by the National Science Foundation and U.S.\nGeological Survey through the Southern California\nEarthquake Center (contribution 379). This is Seismological\nLaboratory of California Institute of Technology contribution 6205.\n\nPublished - 98TC00378.pdf
", "abstract": "Apatite helium thermochronometry provides new constraints on the tectonic history of a recently uplifted crystalline mass adjacent to the San Andreas fault. By documenting aspects of the low-temperature (40\u00b0\u2013100\u00b0C) thermal history of the tectonic blocks of the San Bernardino Mountains in southern California, we have placed new constraints on the magnitude and timing of uplift. Old helium ages (64\u201321 Ma) from the large Big Bear plateau predate the recent uplift of the range and show that only several kilometers of exhumation has taken place since the Late Cretaceous period. These ages imply that the surface of the plateau may have been exposed in the late Miocene and was uplifted only \u223c1 km above the Mojave Desert in the last few Myr by thrusting on the north and south. A similar range in helium ages (56\u201314 Ma) from the higher San Gorgonio block to the south suggests that its crest was once contiguous with that of the Big Bear block and that its greater elevation represents a localized uplift that the Big Bear plateau did not experience. The structure of the San Gorgonio block appears to be a gentle antiform, based on the geometry of helium isochrons and geologic constraints. Young ages (0.7\u20131.6 Ma) from crustal slices within the San Andreas fault zone indicate uplift of a greater magnitude than blocks to the north. These smaller blocks probably experienced \u22653\u20134 km of uplift at rates \u22651.5 mm/yr in the past few Myr and would stand \u22652.5 km higher than the Big Bear plateau if erosion had not occurred. The greater uplift of tectonic blocks adjacent to and within the San Andreas fault zone is more likely the result of oblique displacement along high-angle faults than motion along the thrust fault that bounds the north side of the range. We speculate that this uplift is the result of convergence and slip partitioning associated with local geometric complexities along this strike-slip system. Transpression thus appears to have been accommodated by both vertical displacement within the San Andreas fault zone and thrusting on adjacent structures.", "date": "1998-06", "date_type": "published", "publication": "Tectonics", "volume": "17", "number": "3", "publisher": "American Geophysical Union", "pagerange": "360-378", "id_number": "CaltechAUTHORS:20121121-112609605", "issn": "0278-7407", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121121-112609605", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" }, { "agency": "USGS" }, { "agency": "Southern California Earthquake Center (SCEC)" } ] }, "other_numbering_system": { "items": [ { "id": "379", "name": "Southern California Earthquake Center" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/98TC00378", "primary_object": { "basename": "98TC00378.pdf", "url": "https://authors.library.caltech.edu/records/k8wtb-hdb72/files/98TC00378.pdf" }, "resource_type": "article", "pub_year": "1998", "author_list": "Spotila, James A.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/24d8s-egp92", "eprint_id": 35810, "eprint_status": "archive", "datestamp": "2023-08-22 12:52:15", "lastmod": "2023-10-20 21:11:14", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Montanari-A", "name": { "family": "Montanari", "given": "A." } }, { "id": "Shoemaker-E-M", "name": { "family": "Shoemaker", "given": "E. M." } }, { "id": "Shoemaker-C-S", "name": { "family": "Shoemaker", "given": "C. S." } } ] }, "title": "Geochemical Evidence for a Comet Shower in the Late Eocene", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1998 American Association for the Advancement of Science. Received 13 January 1998; accepted 27 March 1998. We thank P. Weissman for a constructive and thoughtful review and D. Patterson and K. Robinson for assistance with sample preparation. Supported by NASA and by the David and Lucille Packard Foundation through a fellowship award to K.A.F.", "abstract": "Analyses of pelagic limestones indicate that the flux of extraterrestrial helium-3 to Earth was increased for a 2.5-million year (My) period in the late Eocene. The enhancement began \u223c1 My before and ended \u223c1.5 My after the major impact events that produced the large Popigai and Chesapeake Bay craters \u223c36 million years ago. The correlation between increased concentrations of helium-3, a tracer of fine-grained interplanetary dust, and large impacts indicates that the abundance of Earth-crossing objects and dustiness in the inner solar system were simultaneously but only briefly enhanced. These observations provide evidence for a comet shower triggered by an impulsive perturbation of the Oort cloud.", "date": "1998-05-22", "date_type": "published", "publication": "Science", "volume": "280", "number": "5367", "publisher": "American Association for the Advancement of Science", "pagerange": "1250-1253", "id_number": "CaltechAUTHORS:20121205-085724991", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121205-085724991", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" }, { "agency": "David and Lucille Packard Foundation" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.280.5367.1250", "resource_type": "article", "pub_year": "1998", "author_list": "Farley, K. A.; Montanari, A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/5cdd0-wd798", "eprint_id": 35574, "eprint_status": "archive", "datestamp": "2023-08-22 12:50:45", "lastmod": "2023-10-20 19:10:16", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Burnard-P-G", "name": { "family": "Burnard", "given": "P. G." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Turner-G", "name": { "family": "Turner", "given": "G." } } ] }, "title": "Multiple fluid pulses in a Samoan harzburgite", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Samoa; Xenoliths; Fluid inclusions; Helium; Argon", "note": "\u00a9 1998 Elsevier Science B.V.", "abstract": "Noble gases trapped in fluid inclusions in residual mantle xenoliths from Samoa have a wide range in ^4He/^(40)Ar^* which anti-correlates with enrichments in non-atmospheric Ar, Ne and Xe isotopes and with the concentration of ^(40)Ar^* trapped in the mineral. These correlations cannot be due to post-eruption loss of He from the inclusions, but are likely due to mixing of a He-depleted mantle fluid and an unfractionated, plume-derived, fluid that has entrained significant atmospheric noble gases. Mixing of the two fluids occurred within the mantle or at the base of the Samoan lithosphere. Helium loss at depth is implied.", "date": "1998-05-15", "date_type": "published", "publication": "Chemical Geology", "volume": "147", "number": "1-2", "publisher": "Elsevier", "pagerange": "99-114", "id_number": "CaltechAUTHORS:20121120-131917487", "issn": "0009-2541", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-131917487", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0009-2541(97)00175-7", "resource_type": "article", "pub_year": "1998", "author_list": "Burnard, P. G.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/h34fc-y7t04", "eprint_id": 2108, "eprint_status": "archive", "datestamp": "2023-08-22 12:47:14", "lastmod": "2023-10-13 23:12:40", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Neroda\u00ad-E", "name": { "family": "Neroda\u00ad", "given": "E." } } ] }, "title": "Noble gases in the Earth's mantle", "ispublished": "pub", "full_text_status": "public", "keywords": "mantle evolution; atmosphere formation; mantle geochemistry; planetary outgassing; radiogenic isotopes", "note": "\u00a9 1998 by Annual Reviews. \n\nWe thank D Graham, D Hilton, D Porcelli, and D Patterson for helpful comments.\n\nPublished - FARareps98.pdf
", "abstract": "Noble gas isotopic ratios in mantle-derived samples require variability in the time-integrated ratio of volatile to lithophile elements in the Earth. Documentation of mantle \u00b3He/\u2074He variability is becoming increasingly complete, but for the heavier noble gases, the picture is still partly clouded by the effects of atmospheric contamination of mantle samples. Nevertheless, clear variations in mantle Ne, Ar, and Xe isotopic ratios exist, are apparently correlated with \u00b3He/\u2074He, and may be the product of varying degrees of mantle degassing. However, uncertainties in noble gas geochemical behavior and several conflicting observations leave open other possibilities. Recent Ne isotopic data are particularly important because they require that the atmosphere has not been closed to exchange with space. Derivation of much of the atmosphere from a source other than degassing of the mantle is a strong possibility that complicates efforts to model the geochemical evolution of the Earth.", "date": "1998-05", "date_type": "published", "publication": "Annual Review of Earth and Planetary Sciences", "volume": "26", "publisher": "Annual Reviews", "pagerange": "189-218", "id_number": "CaltechAUTHORS:FARareps98", "issn": "0084-6597", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:FARareps98", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1146/annurev.earth.26.1.189", "primary_object": { "basename": "FARareps98.pdf", "url": "https://authors.library.caltech.edu/records/h34fc-y7t04/files/FARareps98.pdf" }, "resource_type": "article", "pub_year": "1998", "author_list": "Farley, K. A. and Neroda\u00ad, E." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/pp32w-tj311", "eprint_id": 35544, "eprint_status": "archive", "datestamp": "2023-08-22 11:55:50", "lastmod": "2023-10-20 19:07:30", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "House-M-A", "name": { "family": "House", "given": "M. A." } }, { "id": "Wernicke-B-P", "name": { "family": "Wernicke", "given": "B. P." }, "orcid": "0000-0002-7659-8358" }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Dumitru-T-A", "name": { "family": "Dimitru", "given": "T. A." } } ] }, "title": "Cenozoic thermal evolution of the central Sierra Nevada,\n California, from (U-Th)/He thermochronometry", "ispublished": "pub", "full_text_status": "restricted", "keywords": "helium; fission-track dating; Sierra Nevada; thermal history", "note": "\u00a9 1997 Elsevier Science B.V. Received 28 March 1997; revised 10 July 1997; accepted 10 July 1997. This study was supported by National Science Foundation grants EAR-9526895, awarded to B. Wernicke, K. Farley, and J. Saleeby and EAR-9417939 to T. Dumitru. Constructive criticism by S. Peacock. C. Naeser, and an anonymous reviewer substantially improved the presentation of this\nmanuscript. [MK]", "abstract": "Apatite(U-Th)/He cooling ages are reported for igneous apatite samples from the central Sierra Nevada and compared to published apatite fission track ages and track length data from the same mineral separates. Helium ages are youngest at low elevations and increase systematically toward higher elevations, ranging from 43 to 84 Ma at Yosemite Valley, 32 to 74 Ma at Kings River Canyon, and 23 to 75 Ma at Mt. Whitney. Helium ages from high elevation samples are generally concordant with corresponding fission track ages, while lower elevation helium ages are substantially younger. Cooling histories inferred from present laboratory derived fission track annealing and helium diffusion models do not match well, suggesting that either helium diffusion rates or fission track annealing rates are miscalibrated at temperatures below about 60\u00b0C for geologic exposure periods. Unlike the fission track results, the helium data do not indicate a very low geothermal gradient in the Sierra Nevada during early to middle Tertiary time.", "date": "1997-10", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "151", "number": "3-4", "publisher": "Elsevier", "pagerange": "167-179", "id_number": "CaltechAUTHORS:20121119-113957873", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121119-113957873", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9526895" }, { "agency": "NSF", "grant_number": "EAR-9417939" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(97)81846-8", "resource_type": "article", "pub_year": "1997", "author_list": "House, M. A.; Wernicke, B. P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/xrkgd-4d706", "eprint_id": 35584, "eprint_status": "archive", "datestamp": "2023-08-22 11:43:47", "lastmod": "2023-10-20 19:11:14", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Love-S-G", "name": { "family": "Love", "given": "S. G." } }, { "id": "Patterson-D-B", "name": { "family": "Patterson", "given": "D. B." } } ] }, "title": "Atmospheric entry heating and helium retentivity of interplanetary dust particles", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1997 Elsevier Science Ltd. Received September 1, 1996; accepted in revised form February 3, 1997. Editorial handling: C. Koeberl. work was supported by NASA. We thank\nD. Brownlee, J.-I. Matsuda, and L. Schultz for careful reviews.", "abstract": "We have modeled atmospheric entry heating of interplanetary dust to characterize the population of particles carrying extraterrestrial He to the seafloor. We find that \u223c0.5% of the mass and \u223c4% of the surface area of the infalling dust transits the atmosphere at temperatures lower than that required for He release (\u223c600\u00b0C). Size-dependent heating causes the particles which retain He to be far smaller than those in the parental interplanetary dust population. The particle-size distribution of He-bearing dust is such that most of the mass is delivered by particles of \u223c20 \u03bcm diameter, while most of the surface area (relevant for surface-correlated constituents, e.g., implanted solar wind He) is carried by particles of \u223c7 \u03bcm diameter. Knowledge of these size distributions allows us to evaluate the possibility of sedimentary redistribution of extraterrestrial dust in the atmosphere and ocean. The size distributions also have important consequences for interpretation of He abundances in seafloor sediment samples that integrate over fairly small areas and times. Sediment samples generally will not record a representative distribution of interplanetary dust but will have a strong tendency to undersample rare large particles. We predict a high degree of variability in replicate He analyses of a single sediment sample, with a mass-correlated He component yielding greater variability than a surface-correlated component. Comparison with sediment measurements confirms such variability and demonstrates excellent agreement with the statistical distribution expected for a surface correlated component, consistent with suggestions that seafloor extraterrestrial He is surface-correlated implanted solar wind or solar flare He. A second important statistical effect is that sediment measurements systematically underestimate the true extraterrestrial He flux, typically by 50%.", "date": "1997-06", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "61", "number": "11", "publisher": "Elsevier", "pagerange": "2309-2316", "id_number": "CaltechAUTHORS:20121120-144139882", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-144139882", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0016-7037(97)00068-9", "resource_type": "article", "pub_year": "1997", "author_list": "Farley, K. A.; Love, S. G.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/9vxkp-4f631", "eprint_id": 35585, "eprint_status": "archive", "datestamp": "2023-08-22 11:43:55", "lastmod": "2023-10-20 19:11:21", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Patterson-D-B", "name": { "family": "Patterson", "given": "D. B." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "McInnes-B-I-A", "name": { "family": "McInnes", "given": "B. I. A." } } ] }, "title": "Helium isotopic composition of the Tabar-Lihir-Tanga-Feni island arc, Papua New Guinea", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1997 Elsevier Science Ltd. Received July 22, 1996; accepted in revised form February 18, 1997. Editorial handling: U. Ott. We wish to thank the Lihir Management Company, Nord Pacific Ltd., and Father Anthony Gendusa for providing invaluable assistance in the collection of the subaerial samples and Master M. Kull and the officers and crew of R.V. SONNE for assistance collecting the submarine samples during EDISON Cruise SO-94. We thank also M. Perfit for reference to unpublished data. We are also indebted to D. Hilton and two anonymous reviewers for their very helpful suggestions. This work was supported by NSF\nOCE-9402159 to KAF.", "abstract": "Helium abundances and isotopic ratios have been measured in samples of geothermal gases, submarine ultramafic xenoliths, and subaerial mafic phenocrysts and xenoliths from the Tabar-LihirTanga-Feni (TLTF) arc in the Bismarck Archipelago of Papua New Guinea. These unusual volcanoes are produced by adiabatic decompression melting of subduction-modified upper mantle and apparently carry an exceptionally large slab-derived component. They, therefore, provide an ideal setting for studying the role of subducted helium in arc volcanoes. Helium isotopic ratios in the geothermal fluids, submarine xenoliths, and most helium-rich subaerial samples indicate the mantle source regions beneath the Tabar Island Group and Lihir Island have ^3He/^4He ratios of about 7.2 times the atmospheric ratio (R_A), whereas the mantle source for Ambitle Island (Feni Group) in the more southern TLTF arc has a lower ratio of about 6.6 R_A. These ratios are only slightly lower than typical depleted upper mantle values of about 8.5 R_A, indicating that even severely slab-modified mantle wedge carries a relatively minor slab-derived helium component. The systematically lower ^3He/^4He ratios of the Ambitle samples are interpreted to reflect a slightly greater slab-derived helium component.\nHelium isotopic ratios as low as 2 R_A, which are correlated with low total helium abundances, were observed in subaerial augitic clinopyroxene phenocrysts. Coexisting olivine and sodium-rich acmitic clinopyroxene have higher helium abundances and isotopic ratios. This isotopic disequilibrium between coexisting mineral phases is interpreted as crustal-level addition of a low ^3He/^4He component to an actively outgassing magma from which different mineral phases trap helium sequentially.", "date": "1997-06", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "61", "number": "12", "publisher": "Elsevier", "pagerange": "2485-2496", "id_number": "CaltechAUTHORS:20121120-144917367", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-144917367", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OCE-9402159" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0016-7037(97)00095-1", "resource_type": "article", "pub_year": "1997", "author_list": "Patterson, D. B.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/b8pj8-4s838", "eprint_id": 33477, "eprint_status": "archive", "datestamp": "2023-08-22 11:43:35", "lastmod": "2023-10-18 19:57:42", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "John M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Valley-J-W", "name": { "family": "Valley", "given": "John W." } }, { "id": "Hauri-Erik-H", "name": { "family": "Hauri", "given": "Erik" }, "orcid": "0000-0002-7449-4774" }, { "id": "Craig-Harmon", "name": { "family": "Craig", "given": "Harmon" } }, { "id": "Hart-Stanley-R", "name": { "family": "Hart", "given": "Stanley R." } }, { "id": "Stolper-E-M", "name": { "family": "Stolper", "given": "Edward M." }, "orcid": "0000-0001-8008-8804" } ] }, "title": "Oxygen isotope variations in ocean island basalt phenocrysts", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1997 Elsevier Science Ltd.\n\n Received 24 June 1996. Accepted 7 February 1997. Available online 8 June 1998. \n\nWe thank A. Hofmann for helpful discussions of this work, Mike Spicuzza for assistance in the stable isotope laboratory at the University of Wisconsin, and Dominique Weis and Mukul Sharma for contributing samples for this study. This manuscript was improved by the thorough reviews of Emi Ito and Barry Hanan. This work was funded by NSF EAR-9628142, -9303975, and -9117588 to EMS and 93-04372 to JWV, and DOE grants DEFG03-85ER13445 to EMS and 93ER14389 to JWV. \n\nEditorial handling: F. A. Frey.", "abstract": "Oxygen isotope ratios are reported for olivine phenocrysts from sixty-seven samples of ocean island basalts (OlBs), mid-ocean ridge basalts (MORBs), and related peridotites, including representatives of the various isotopic endmembers defined by radiogenic isotope ratios. OIBs are more homogeneous in \u03b4^(18)O by this analysis than suggested by previous studies of whole rocks and glasses. Most 0I13 samples have oxygen isotope ratios within a restricted range (\u03b4^(18)O_(olivine) = 5.0\u20135.4\u2030), comparable to those of olivines in peridotites from ophiolites, in most peridotitic mantle xenoliths, and inferred for the sources of mid-ocean ridge basalts. The exceptions are EM2 lavas, which are enriched in ^(18)O (\u03b4^(18)_(olivine) = 5.4\u20136.1\u2030), and a small number of samples characterized by low ^3He/^4He and distinctive lead isotope ratios, which are ^(18)O depleted (\u03b4^(18)O = 4.7-5.1\u2030). The observed range in \u03b4^(18)O and the correlations with radiogenic isotope ratios are similar to those observed in a detailed study of Hawaiian samples (Eiler et al., 1996b). These results indicate that recycled crust and/or sediments (or the imprint of extensive metasomatism by fluids derived from such materials) is present as at most a small mass fraction (\u2a85 l%) in the mantle sources of most OIBs. The results on most EM2 lavas are consistent with the presence of \u223c2\u20136% recycled sediment in their source regions. Low \u03b4^(18)O values in OIBs can be produced by assimilation of altered lavas from high-levels in the volcanic edifice, assimilation of the oceanic crust underlying the volcano, or incorporation of subducted oceanic crust in mantle sources. The only consistent correlatives with low \u03b4^(18)O are low ^3He/^4He and anomalous ^(207)Pb/^(204)Pb-^(206)Pb/^(204)Pb relationships, and most of the low-\u03b4^(18)O samples can be explained by contamination by the underlying oceanic crust or volcanic edifice. High-^3He/^4He lavas are indistinguishable from MORBs and most other OIBs in terms of \u03b4^(18)O, suggesting that to the extent that the lower mantle is sampled by hotspot volcanism, there is no significant vertical stratification in oxygen isotope ratios in the mantle.", "date": "1997-06", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "61", "number": "11", "publisher": "Elsevier", "pagerange": "2281-2293", "id_number": "CaltechAUTHORS:20120823-103638494", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120823-103638494", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9628142" }, { "agency": "NSF", "grant_number": "EAR-9303975" }, { "agency": "NSF", "grant_number": "EAR-9117588" }, { "agency": "NSF", "grant_number": "EAR-93-04372" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-FG03-85ER13445" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-FG03-93ER14389" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0016-7037(97)00075-6", "resource_type": "article", "pub_year": "1997", "author_list": "Eiler, John M.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3kmwx-5yh25", "eprint_id": 35443, "eprint_status": "archive", "datestamp": "2023-08-22 11:30:20", "lastmod": "2023-10-20 16:20:42", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wolf-R-A", "name": { "family": "Wolf", "given": "R. A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Silver-L-T", "name": { "family": "Silver", "given": "L. T." } } ] }, "title": "Assessment of (U-Th)/He thermochronometry: The low-temperature history of the San Jacinto mountains, California", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1997 by the Geological Society of America. \n\nManuscript received June 19, 1996. Revised manuscript received September 26, 1996. Manuscript accepted October 21, 1996. \n\nSupported by the National Science Foundation. Detailed reviews by Trevor Dumitru and Mark Brandon greatly improved this paper. We thank Brian Wernicke for helpful comments throughout the course of this work.\n\nSubmitted - Assessment_of__U-Th_-He_thermochronometry.pdf
", "abstract": "(U-Th)/He ages have been measured on igneous apatites from the San Jacinto mountains, a high region at the junction of the Peninsular and Transverse Ranges, to investigate the potential of this technique for thermochronometry of slowly cooled rocks. Helium ages from 79 to 17 Ma are younger than ages obtained by other dating techniques, including apatite fission-track counting, and are consistent with laboratory experiments that indicate this system has a uniquely low closure temperature. Helium ages are strongly correlated with elevation and record the latest low-temperature thermal evolution of the range. They suggest relative tectonic quiescence in the latest Cretaceous through mid-Tertiary and provide no evidence for rapid unroofing of the block during this period. Nor do they obviously require a large degree of uplift associated with convergence between the Transverse and Peninsular ranges in the last few million years. Helium ages document modest westward tilting of the block (\u223c7\u00b0) and a significant vertical component of motion on the block's bounding faults after helium retention began. This work suggests that apatite helium ages record low-temperature tectonic and thermal histories that are not apparent from other dating techniques.", "date": "1997-01", "date_type": "published", "publication": "Geology", "volume": "25", "number": "1", "publisher": "Geological Society of America", "pagerange": "65-68", "id_number": "CaltechAUTHORS:20121113-154436415", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121113-154436415", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/0091-7613(1997)025<0065:AOUTHT>2.3.CO;2", "primary_object": { "basename": "Assessment_of__U-Th_-He_thermochronometry.pdf", "url": "https://authors.library.caltech.edu/records/3kmwx-5yh25/files/Assessment_of__U-Th_-He_thermochronometry.pdf" }, "resource_type": "article", "pub_year": "1997", "author_list": "Wolf, R. A.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/a2qze-vtt20", "eprint_id": 35563, "eprint_status": "archive", "datestamp": "2023-08-22 11:18:15", "lastmod": "2023-10-20 19:08:51", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wolf-R-A", "name": { "family": "Wolf", "given": "R. A." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Silver-L-T", "name": { "family": "Silver", "given": "L. T." } } ] }, "title": "Helium diffusion and low-temperature thermochronometry of apatite", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1996 Elsevier Science Ltd. Received January 10, 1996; accepted in revised form June 8, 1996. Editorial handling: D. E. Fisher. This work was supported by the National Science Foundation. We thank M. Harrison and M. Grove for helpful suggestions and P. Damon and an anonymous reviewer for their comments on the manuscript.", "abstract": "To investigate the potential of the (U-Th)/He system for low-temperature thermochronometry, we have studied helium diffusion and have measured helium ages on Durango fluorapatite and on apatites from a gabbro and two tonalites from the Peninsular Ranges Batholith. Diffusivity at moderate to very low temperatures (as low as 80\u00b0C) was measured to high analytical precision using long duration incremental outgassing experiments. All four apatites displayed remarkably similar helium diffusion behavior. Helium loss apparently occurs via volume diffusion from subgrain domains (<60 \u03bcm) which are nearly identical in size in all samples. At temperatures below 290\u00b0C, diffusivity obeys a highly linear Arrhenius relationship with an implied activation energy of about 36 kcal/mol. Above this temperature, diffusivity deviates from linearity toward lower activation energies. This transition does not arise from multiple diffusion domains, but rather from a reversible change in the physical mechanism of helium diffusion. For thermochronometric purposes the high-temperature diffusion behavior is largely irrelevant because essentially no helium is retained over geologic time at temperatures above 290\u00b0C. Using the results from the low-temperature regime, all samples yield helium closure temperatures in the range 75 \u00b1 7\u00b0C. This value is independent of chemical composition and grain size of the apatites, suggesting that a single closure temperature may apply to a wide range of samples. The (U-Th)/He ages of these apatites (17\u2013120 Ma) range from a small fraction to nearly 100% of the crystallization age of their host rocks, and are consistent with a low-temperature thermochronometric interpretation. These results strongly support previous suggestions that (U-Th)/He dating of apatite can provide high precision chronometry of very low temperature geological events.", "date": "1996-11", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "60", "number": "21", "publisher": "Elsevier", "pagerange": "4231-4240", "id_number": "CaltechAUTHORS:20121120-104629253", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-104629253", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0016-7037(96)00192-5", "resource_type": "article", "pub_year": "1996", "author_list": "Wolf, R. A.; Farley, K. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3xyv5-0y327", "eprint_id": 33484, "eprint_status": "archive", "datestamp": "2023-08-22 11:18:08", "lastmod": "2023-10-18 20:05:02", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "John M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Valley-J-W", "name": { "family": "Valley", "given": "John W." } }, { "id": "Hofmann-A-W", "name": { "family": "Hofmann", "given": "Albrecht W." } }, { "id": "Stolper-E-M", "name": { "family": "Stolper", "given": "Edward M." }, "orcid": "0000-0001-8008-8804" } ] }, "title": "Oxygen isotope constraints on the sources of Hawaiian volcanism", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Hawaii; volcanism; basalts; O-18/O-16", "note": "\u00a9 1996 Elsevier Science B.V. \n\nReceived 16 February 1996. Revised 5 September 1996. Accepted 7 September 1996. Available online 26 February 1999. \n\nWe thank Dave Clague, Fred Frey, Mike Garcia, and Don Thomas for graciously supplying samples for this study, John Lassiter, Mark Kurz, Erik Hauri and Mike Rhodes for sharing data prior to their publication, Mike Spicuzza and Nami Kitchen for assistance in the stable isotope laboratory at the University of Wisconsin, and Fred Frey, Emi Ito and Colin MacPherson for thorough reviews of this manuscript. This work was funded by NSF-9303975 and -9 I 17588 to EMS and 93-04372 to JWV, and DOE grants DEFG03-85ERl3445 to EMS and 93ERl4389 to JWV.", "abstract": "We have measured oxygen isotope ratios in 99 separates of olivine and 14 separates of plagioclase or glass from Hawaiian lavas. These data confirm that the source(s) of some Hawaiian basalts are lower in \u03b4^(18)O than peridotite xenoliths and the source region for mid-ocean ridge basalts (MORB). Our data document correlations between oxygen and radiogenic isotope ratios and consistent differences in \u03b4^(18)O between volcanoes. Low values of \u03b4^(18)O are associated with a 'depleted' component that is relatively high in ^(206)Pb/^(204)Pb, low in ^3He/^4He, and anomalously low in ^(207)Pb/^(204)Pb relative to ^(206)Pb/^(204)Pb. This component is preferentially sampled in lavas from the so-called Kea trend volcanoes (Kilauea, Mauna Kea, Kohala and Haleakala).\n\nLow \u03b4^(18)O values in the 'Kea' component suggest that it is hydrothermally altered oceanic crust. The similarity of the Kea end member to Pacific MORB in terms of Sr, Nd, and Pb isotope ratios further suggests that this component is assimilated from the local Pacific plate in subcrustal magma chambers. Anomalous ^(206)Pb/^(204)Pb-^(207)Pb/^(204)Pb relationships indicate recent enrichment in U/Pb in this component and further support the hypothesis that this component is young ( < 10^8 yr) Pacific crust. The isotopic distinctions between Loa and Kea trend volcanoes implies a systematic difference in the magma supply and plumbing systems of volcanoes on these two trends.\n\nSamples from Lanai and Koolau have 'enriched' radiogenic isotope compositions (radiogenic Sr and non-radiogenic Nd and Pb) and higher \u03b4^(18)O than typical upper mantle values, suggesting the incorporation of recycled sediment and/or oceanic crust in their sources. Other isotopic end members to Hawaiian lavas (e.g., high ^3He/^4He and post-erosional lavas) have \u03b4^(18)O values within the range typical of the upper mantle.", "date": "1996-11", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "144", "number": "3-4", "publisher": "Elsevier", "pagerange": "453-467", "id_number": "CaltechAUTHORS:20120823-113027657", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120823-113027657", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9303975" }, { "agency": "NSF", "grant_number": "EAR-9117588" }, { "agency": "NSF", "grant_number": "EAR-93-04372" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-FG03-85ER13445" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-FG03-93ER14389" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0012-821X(96)00170-7", "resource_type": "article", "pub_year": "1996", "author_list": "Eiler, John M.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/evb39-kn857", "eprint_id": 35583, "eprint_status": "archive", "datestamp": "2023-08-22 11:18:23", "lastmod": "2023-10-20 19:11:06", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Wolf-R-A", "name": { "family": "Wolf", "given": "R. A." } }, { "id": "Silver-L-T", "name": { "family": "Silver", "given": "L. T." } } ] }, "title": "The effects of long alpha-stopping distances on (U-Th)/He ages", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1996 Elsevier Science Ltd. Received January 10, 1996; accepted in revised form June 8, 1996. Editorial handling: D. E. Fisher. This work was funded by the National Science\nFoundation. We thank P. Damon and an anonymous reviewer for\nhelpful comments on the manuscript.", "abstract": "A mathematical framework for quantitative evaluation of alpha-stopping effects on (U-Th)/He ages has been developed. Alpha stopping ranges in the ^(238)U, ^(235)U, and ^(232)Th chains vary between \u223c10 and \u223c30 \u03bcm, depending on decay energy and density/composition of the stopping medium. In the case of U- and Th-rich accessory minerals (e.g. apatite, zircon, titanite), the dominant effect of long stopping distances is alpha ejection to adjacent minerals. For grains smaller than a few hundred microns in minimum dimension, ejection effects will cause measured helium ages to substantially underestimate true ages. For example, a sphere of 100 \u03bcm radius retains only \u223c82% of its alphas. For a homogeneous distribution of parent nuclides, the fraction of alphas ejected is \u223c 1/4 of the mean alpha range multiplied by the crystal surface to volume ratio, independent of geometry. Removal of the outer 20 \u03bcm of a crystal prior to dating eliminates the region which has experienced alpha loss, but may lead to erroneous ages when crystals are strongly zoned with respect to uranium and thorium. By careful characterization of four sieved apatite separates from a single sample, we show that it is possible to accurately correct (U-Th)/He ages for alpha ejection even when ejection exceeds 35% of total decays. Our results are useful for identifying the size and shape of grains which are best suited for (U-Th)/He dating and provide the basis for correcting ages when ejection effects are significant. This work underscores that meaningful (U-Th)/He ages require either large crystals, or correction of measured ages for alpha ejection.", "date": "1996-11", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "60", "number": "21", "publisher": "Elsevier", "pagerange": "4223-4229", "id_number": "CaltechAUTHORS:20121120-143017682", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-143017682", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/S0016-7037(96)00193-7", "resource_type": "article", "pub_year": "1996", "author_list": "Farley, K. A.; Wolf, R. A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/vrzmn-rh067", "eprint_id": 37445, "eprint_status": "archive", "datestamp": "2023-08-22 10:42:06", "lastmod": "2023-10-23 17:28:22", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Patterson-D-B", "name": { "family": "Patterson", "given": "D. B." } } ] }, "title": "A 100-kyr periodicity in the flux\n of extraterrestrial ^3He\n to the sea floor", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1995 Nature Publishing Group\nReceived 19 June; accepted 30 October 1995; 07 December 1995\nThis work was supported by the NSF. We thank W. Alvarez for early\ndiscussions which led to th1s work, R. Muller, F. Marcantonio, A. Anbar and S. Love for helpful\ndiscussions. R. Wolf for analytical assistance, and S. Dermott, R. Poreda and W. Ruddiman for\ncareful rev1ews.", "abstract": "Most of the helium-3 in oceanic sediments comes from interplanetary\ndust particles (IDPs), and can therefore be used to infer the\naccretion rate of dust to the Earth through time. ^3He records\nfrom slowly accumulating pelagic clays indicate that the accretion\nrate varies considerably over millions of years, probably owing to\ncometary and asteroidal break-up events. Muller and MacDonald\nhave proposed that periodic changes in this accretion rate due to\na previously unrecognized 100-kyr periodicity in the Earth's orbital\ninclination might account for the prominence of this frequency in\nclimate records of the past million years. Here we report variations\nin the 3^He flux to the sea floor that support this idea. We\nfind that the flux recorded in rapidly accumulating Quaternary\nsediments from the Mid-Atlantic Ridge oscillates with a period of\nabout 100 kyr. We cannot yet say, however, whether the 100-kyr\nclimate cycle is a consequence of, a cause of, or an effect independent\nof these periodic changes", "date": "1995-12-07", "date_type": "published", "publication": "Nature", "volume": "378", "number": "6557", "publisher": "Nature Publishing Group", "pagerange": "600-603", "id_number": "CaltechAUTHORS:20130311-134139514", "issn": "0028-0836", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130311-134139514", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/378600a0", "resource_type": "article", "pub_year": "1995", "author_list": "Farley, K. A. and Patterson, D. B." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/0n445-djh79", "eprint_id": 33544, "eprint_status": "archive", "datestamp": "2023-08-22 10:37:10", "lastmod": "2023-10-18 20:24:45", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "John M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Valley-J-W", "name": { "family": "Valley", "given": "John W." } }, { "id": "Stolper-E-M", "name": { "family": "Stolper", "given": "Edward M." }, "orcid": "0000-0001-8008-8804" }, { "id": "Hauri-Erik-H", "name": { "family": "Hauri", "given": "Eric H." }, "orcid": "0000-0002-7449-4774" }, { "id": "Craig-Harmon", "name": { "family": "Craig", "given": "Harmon" } } ] }, "title": "Oxygen isotope evidence against bulk recycled sediment in the mantle sources of Pitcairn Island lavas", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1995 Nature Publishing Group. \n\nReceived 10 April; accepted 8 August 1995. \n\nWe thank J. Woodhead for sharing unpublished analysis of seamount glasses, W. White for comments on the manuscript, M. Spicuzza and N. Kitchen for assistance in the stable-isotope laboratory, and P. Carpenter for help with electron microprobe analysis. This research was supported in part by DOE and NSF.", "abstract": "The hypothesis that subducted sediments survive dehydration and/or melting in subduction zones to become long-lived geo-chemical reservoirs in the mantle has gained support in recent years. Evidence for such reservoirs is found in the geochemistry of ocean island basalts (OIBs), some of which have isotopic and trace-element characteristics plausibly associated with ancient sedimentary components. In particular, the EM1 mantle end-member has been identified, principally on the basis of strontium, neodymium and lead isotopes, and has been proposed to carry a large sediment fraction. Oxygen isotopes should be sensitive indicators of subducted sediment in the sources of OIBs because minerals that interact with water at low temperatures near the Earth's surface (during weathering, for example) become enriched in ^(18)O relative to ^(16)O (ref. 6). We report here the ^(18)O:^(16)O ratios of phenocrysts from basalts from Pitcairn Island (southeast Pacific Ocean), which, together with the nearby Pitcairn seamounts, contain among the most extreme EM1 signatures known. We find the oxygen isotope ratios of the phenocrysts to be indistinguishable from the average for mantle peridotite. These results show that the end-member EM1 signature can be produced in the absence of substantial (>l-2%) recycled sediment in the mantle.", "date": "1995-09-14", "date_type": "published", "publication": "Nature", "volume": "377", "number": "6545", "publisher": "Nature Publishing Group", "pagerange": "138-141", "id_number": "CaltechAUTHORS:20120827-082431654", "issn": "0028-0836", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120827-082431654", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/377138a0", "resource_type": "article", "pub_year": "1995", "author_list": "Eiler, John M.; Farley, Kenneth A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/aa70a-tvm43", "eprint_id": 38030, "eprint_status": "archive", "datestamp": "2023-08-22 10:32:37", "lastmod": "2023-10-23 19:42:13", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Cenozoic variations in the flux of interplanetary dust recorded by ^3He in a deep-sea sediment", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1995 Nature Publishing Group. Received 15 March; accepted 9 June 1995. I thank F. Kyte, K. Turekian and B. J. Pegram for helpful comments and for supplying samples, and G. J. Flynn for a helpful review. This work was supported by\nthe Ocean Sciences Division of the US National Science Foundation.", "abstract": "Helium-3 concentrations and ^3He/^4He ratios in modern pelagic sediments are known to be far in excess of terrestrial values as a result of micrometeorite fallout. Here I report that extraterrestrial helium is easily detected in a pelagic clay core dating back more than 70 Myr. The remarkable preservation of the extraterrestrial signature arises from high retention of ^3He within interplanetary dust particles, coupled with loss of radiogenic ^4He from terrestrial mineral grains. The core provides a continuous record of the fallout of extraterrestrial helium for the Cenozoic era. This record suggests that there have been significant variations in the influx of interplanetary dust through time, probably related to asteroidal breakup events or the passage of comets through the inner Solar System. The results also show ^3He to be a far more sensitive tracer of the interplanetary dust flux than is iridium.", "date": "1995-07-13", "date_type": "published", "publication": "Nature", "volume": "376", "number": "6536", "publisher": "Nature Publishing Group", "pagerange": "153-156", "id_number": "CaltechAUTHORS:20130419-081334817", "issn": "0028-0836", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130419-081334817", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF Ocean Sciences Division" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/376153a0", "resource_type": "article", "pub_year": "1995", "author_list": "Farley, K. A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/506xe-86b83", "eprint_id": 65615, "eprint_status": "archive", "datestamp": "2023-08-22 10:30:47", "lastmod": "2024-01-13 16:45:27", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "J. M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K." }, "orcid": "0000-0002-7846-7546" }, { "id": "Valley-J-W", "name": { "family": "Valley", "given": "J. W." } }, { "id": "Hofmann-A-W", "name": { "family": "Hofmann", "given": "A. W." } }, { "id": "Stolper-E-M", "name": { "family": "Stolper", "given": "E. M." }, "orcid": "0000-0001-8008-8804" } ] }, "title": "Oxygen Isotope Constraints on the Sources of Ocean Island Basalts", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1995 Alfred-Wegener-Stiftung.\n\nPublished - Eiler_1995p34.pdf
", "abstract": "Oxygen isotope ratios in phenocrysts from ocean island basalts (OIB) can place\nconstraints on the origins of their mantle sources. Values of \u03b4^(18)O in olivines from\nalkali basalts from Pitcairn Island (which have the extreme \"EM1\" signature\nbased on radiogenic isotopes) are equal to those of olivines from average mantle\nperidotite (based on studies of mantle xenoliths and the MORB source region) .\nThis result suggests that the amount of recycled continental sediment in Pitcairn\nIsland EM1 sources is less than ~0.75%. Based on studies of olivine phenocrysts,\nthe sources of both the plume component of Hawaiian lavas and of all measured\nJuan Fernandez (\"PHEM\") samples also have oxygen isotope compositions\nindistinguishable from average upper mantle peridotite. If these OIB sources\ncome from the lower mantle, it is implied to have an oxygen isotope ratio similar to\nthe upper mantle. Low ^(18)O/^(16)O olivines from some Hawaiian lavas are associated\nwith a more MORB-like He and radiogenic isotope component, possibly recycled\nbut also consistent with contamination from the base of the modern Pacific plate.", "date": "1995-07", "date_type": "published", "publisher": "Alfred-Wegener-Stiftung", "id_number": "CaltechAUTHORS:20160323-093740656", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160323-093740656", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Anderson-D-L", "name": { "family": "Anderson", "given": "Don L." } }, { "id": "Hart-Stanley-R", "name": { "family": "Hart", "given": "Stanley R." } }, { "id": "Hofmann-A-W", "name": { "family": "Hofmann", "given": "Albrecht W." } }, { "id": "Lehnert-K", "name": { "family": "Lehnert", "given": "K." } } ] }, "primary_object": { "basename": "Eiler_1995p34.pdf", "url": "https://authors.library.caltech.edu/records/506xe-86b83/files/Eiler_1995p34.pdf" }, "resource_type": "book_section", "pub_year": "1995", "author_list": "Eiler, J. M.; Farley, K.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/g658y-b5c16", "eprint_id": 35446, "eprint_status": "archive", "datestamp": "2023-08-22 10:27:39", "lastmod": "2023-10-20 16:20:55", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Rapid cycling of subducted sediments into the Samoan mantle plume", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1995 Geological Society of America.\nManuscript received October 28, 1994.\nRevised manuscript received February 9, 1995.\nManuscript accepted February 27, 1995.\nSupported by National Science Foundation\ngrants EAR-93-04267 and EAR-92-04822. I\nthank J. Natland, R. Poreda, E. Stolper, G. Rossman,\nand J. Eiler for various contributions to this\neffort. The manuscript benefited from reviews by\nW. M. White and A. Cohen.", "abstract": "Harzburgite xenoliths from the Samoan hotspot carry extraordinarily enriched Sr-Nd-Pb isotopic ratios previously attributed to metasomatism by a carbonatitic fluid derived from recycled sediments. I describe here the gas composition and microthermometric properties of fluid inclusions that have trapped this unusual agent. The inclusions are dominantly pure CO_2 and were apparently formed at the base of the crust. They have high ^3He/^4He ratios (12 times the atmospheric ratio), inconsistent with the radiogenic values expected for recycled sediments. Furthermore, inclusion C/^3He ratios of \u223c3 \u00d7 10^9 are indistinguishable from typical mantle values and are far lower than those in sediments (>10^(11)). These striking observations imply that little of the helium and carbon in the metasomatic fluid was derived from the recycled source required by the Sr-Nd-Pb isotopes. The metasomatic fluid is probably a product of mixing within the Samoan hot spot of a volatile-rich high ^3He/^4He plume melt and recycled sediments. The retention of high ^3He/^3He ratios in such a mixture requires very rapid cycling of the sedimentary component through the mantle (probably <10^7 yr), rather than the billions of years often envisaged. This time scale indicates involvement of material recently returned to the mantle at the nearby Tonga Trench, and pelagic sediments near the trench have approximately the requisite geochemical signature. The unique isotopic characteristics of the Samoan plume likely arise from its unusual tectonic setting at the northern terminus of subduction in the Tonga Trench.", "date": "1995-06", "date_type": "published", "publication": "Geology", "volume": "23", "number": "6", "publisher": "Geological Society of America", "pagerange": "531-534", "id_number": "CaltechAUTHORS:20121114-074259719", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121114-074259719", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-93-04267" }, { "agency": "NSF", "grant_number": "EAR-92-04822" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/0091-7613(1995)023<0531:RCOSSI>2.3.CO;2", "resource_type": "article", "pub_year": "1995", "author_list": "Farley, K. A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/fhp27-t5a94", "eprint_id": 35606, "eprint_status": "archive", "datestamp": "2023-08-22 10:22:00", "lastmod": "2023-10-20 19:12:51", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Maier-Reimer-E", "name": { "family": "Maier-Reimer", "given": "E." } }, { "id": "Schlosser-P", "name": { "family": "Schlosser", "given": "P." } }, { "id": "Broecker-W-S", "name": { "family": "Broecker", "given": "W. S." } } ] }, "title": "Constraints on mantle ^3He fluxes and deep-sea circulation from an oceanic general circulation model", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1995 American Geophysical Union. Received April 7, 1994; revised October 24, 1994; accepted November 2, 1994. We thank Keith Dixon for a thorough and constructive review of this manuscript. This work was supported by NSF Grant OCE-9111404 (P.S.). This is LDEO contribution number\n5293.\n\nPublished - 94JB02913.pdf
", "abstract": "We have simulated the steady-state distribution of helium in the deep sea to investigate the magnitude and spatial and temporal variability of mantle degassing and to characterize deep-sea circulation and ventilation. The simulation was produced by linking a simple source function for helium injected at mid-ocean ridges with an oceanic general circulation model (GCM). By assuming that the flux of mantle helium is linearly proportional to the seafloor spreading rate and by using previous estimates for the total flux of mantle helium into the oceans, the GCM yields an oceanic ^3He distribution which is in qualitative agreement with observations both in overall magnitude and in general distribution. This provides new evidence that the flux of mantle ^3He into the oceans is about 1000 mol/yr and that mid-ocean ridges are the dominant source of mantle helium. Although the match with observations is good in the Pacific and Indian Oceans, the simulated ^3He anomalies throughout the Atlantic Ocean are much higher than has been measured. Because the GCM is thought to reproduce Atlantic circulation reasonably well, this discrepancy suggests an error in the helium source function. Either helium injection is not a linear function of seafloor emplacement rate, or eruption and concomitant degassing are highly episodic at the slow spreading rates characteristic of the Mid-Atlantic Ridge (MAR). The latter explanation would imply minimal volcanic activity along the entire length of the MAR over the last few centuries. In addition to constraints on the degassing flux, our work provides information on the transport and ventilation of deep ocean waters and constrains the degree to which current GCMs can reproduce deep-water circulation patterns. While the results generally support the GCM's abyssal circulation, our simulation reveals regions of overly-intense lateral diffusion and upwelling in the model, particularly in the equatorial Pacific. Similarly, there appears to be insufficient production of He-ventilated bottom waters in the model Antarctic. These observations suggest that further refinement of the GCM abyssal circulation is required.", "date": "1995-03-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "100", "number": "B3", "publisher": "American Geophysical Union", "pagerange": "3829-3839", "id_number": "CaltechAUTHORS:20121121-111551304", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121121-111551304", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OCE-9111404" } ] }, "other_numbering_system": { "items": [ { "id": "5293", "name": "LDEO" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/94JB02913", "primary_object": { "basename": "94JB02913.pdf", "url": "https://authors.library.caltech.edu/records/fhp27-t5a94/files/94JB02913.pdf" }, "resource_type": "article", "pub_year": "1995", "author_list": "Farley, K. A.; Maier-Reimer, E.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/acdxs-0b254", "eprint_id": 35456, "eprint_status": "archive", "datestamp": "2023-08-22 10:10:42", "lastmod": "2024-01-13 05:56:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Patterson-Desmond", "name": { "family": "Patterson", "given": "Desmond" } }, { "id": "McInnes-Brent", "name": { "family": "McInnes", "given": "Brent" } } ] }, "title": "He-isotopic investigation of geothermal gases from the Tabar-Lihir-Tanga-Feni Arc and Rabaul, Papua New Guinea", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1995 American Institute of Physics.\nWe wish to thank the Lihir Management Company and Father Tony Gendusa for providing\ninvaluable assistance in collecting these samples. We also thank H. Craig for allowing us to cite his\nunpublished data from the Bismarck Archipelago. H. Hiyagon provided a helpful review. This work\nwas supported by NSF OCE-9402159 to KAF.\n\nPublished - Farley_p81.pdf
", "abstract": "In order to investigate the behavior of slab-derived volatiles in the subduction environment,\nhelium isotope ratios have been measured in geothermal gases from the Tabar-Lihir-TangaFeni\n(TLTF) chain in the Bismarck Archipelago of Papua New Guinea. As recorded by several\ngeochemical tracers, these volcanos carry an exceptionally large slab-derived component, and therefore\nmay provide new insights to the old question of volatiles in subduction zones. Geothermal\ngases from Lihir Island have homogeneous ^3He/^4He ratios of 7.18\u00b10.07 times the atmospheric ratio\n(R_A), while those from Ambitle Island (Feni Group) have lower ratios of 6.61\u00b10.13 R_A. These\n^3He/^4He ratios are within the range defined by more-typical arc volcanos, but lie at the low end of\nthe spectrum observed in arc volcanos erupted through purely oceanic crust. Although a small slab-derived\nsignature (^3He/^4He ratio lower than depleted mantle) exists in the TLTF gases, these data\ndemonstrate that even in volcanos with a comparatively large slab component, He is overwhelmingly\nderived from the depleted mantle wedge. This observation further confirms the relative insensitivity\nof He isotopes to the presence of slab fluids.\nHe isotope ratios of 6.25 R_A were measured in geothermal gases from the Rabaul Caldera\non New Britain Island. Coincidentally, these samples were taken six months prior to the major\n1994 eruption at Rabaul. In conjunction with samples taken from the same locality 8 years earlier,\nthese data allow us to test whether increasing He isotope ratios associated with fresh ascending\nmagmas precede volcanic eruptions. Although some of the 1986 samples had much lower ^3He/^4He\nratios (5 R_A than observed in 1994, one did not. We thus find no strong evidence for a systematic\nrise in the He isotope ratio of the Rabaul fluids between 1986 and 1994. If a ^3He/^4He increase did\nprecede the Rabaul eruption, then it occurred either prior to 1986 or sometime between our 1994\nsampling and the eruption.", "date": "1995", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "New York", "pagerange": "81-90", "id_number": "CaltechAUTHORS:20121114-103503801", "isbn": "9781563964091", "book_title": "Volatiles in the Earth and Solar System", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121114-103503801", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OCE-9402159" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth A." } } ] }, "primary_object": { "basename": "Farley_p81.pdf", "url": "https://authors.library.caltech.edu/records/acdxs-0b254/files/Farley_p81.pdf" }, "resource_type": "book_section", "pub_year": "1995", "author_list": "Farley, K. A.; Patterson, Desmond; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/539yf-r5h42", "eprint_id": 39481, "eprint_status": "archive", "datestamp": "2023-08-22 10:11:07", "lastmod": "2023-10-24 16:50:48", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "J. M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K." }, "orcid": "0000-0002-7846-7546" }, { "id": "Valley-J-W", "name": { "family": "Valley", "given": "J. W." } }, { "id": "Hofmann-A-W", "name": { "family": "Hofmann", "given": "A. W." } }, { "id": "Stolper-E-M", "name": { "family": "Stolper", "given": "E. M." }, "orcid": "0000-0001-8008-8804" } ] }, "title": "Oxygen isotope constraints on the sources of ocean island basalts", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1995 Alfred-Wegener-Stiftung.", "abstract": "Oxygen isotope ratios in phenocrysts from ocean island basalts (OIB) can place\nconstraints on the origins of their mantle sources. Values of \u03b4^(18)O in olivines from\nalkali basalts from Pitcairn Island (which have the extreme \"EM1\" signature\nbased on radiogenic isotopes) are equal to those of olivines from average mantle\nperidotite (based on studies of mantle xenoliths and the MORB source region) ,\nThis result suggests that the amount of recycled continental sediment in Pitcairn\nIsland EM1 sources is less than ~0.75%. Based on studies of olivine phenocrysts,\nthe sources of both the plume component of Hawaiian lavas and of all measured\nJuan Fernandez (\"PHEM\") samples also have oxygen isotope compositions\nindistinguishable from average upper mantle peridotite. If these OIB sources\ncome from the lower mantle, it is implied to have an oxygen isotope ratio similar to\nthe upper mantle. Low ^(18)O/^(16)O olivines from some Hawaiian lavas are associated\nwith a more MORB-like He and radiogenic isotope component, possibly recycled\nbut also consistent with contamination from the base of the modern Pacific plate.", "date": "1995", "date_type": "published", "publication": "Terra Nostra", "volume": "3", "publisher": "Alfred-Wegener-Stiftung", "pagerange": "34-37", "id_number": "CaltechAUTHORS:20130722-081647914", "issn": "0946-8978", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130722-081647914", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "resource_type": "article", "pub_year": "1995", "author_list": "Eiler, J. M.; Farley, K.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/nrxtp-eaz62", "eprint_id": 39836, "eprint_status": "archive", "datestamp": "2023-08-22 10:11:21", "lastmod": "2023-10-24 17:14:28", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "John M." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "Kenneth" }, "orcid": "0000-0002-7846-7546" }, { "id": "Stolper-E-M", "name": { "family": "Stolper", "given": "Edward M." }, "orcid": "0000-0001-8008-8804" }, { "id": "Valley-J-W", "name": { "family": "Valley", "given": "John W." } }, { "id": "Craig-Harmon", "name": { "family": "Craig", "given": "Harmon" } } ] }, "title": "Oxygen isotope ratios in phenocrysts from Pitcairn island: constraints on recycled sediment in the \"EM1\" enriched mantle", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1995 Geological Society of America.", "abstract": "The Pitcairn hotspot (southeast Pacific Ocean) carries the strongest EM1 signature known in oceanic\nlavas, both in rocks from Pitcairn Island and from the nearby Pitcairn seamounts. We have measured\noxygen isotope ratios by laser fluorination of phenocrysts from Pitcairn Island alkali basalts variably\nenriched in the EMI mantle end member (defined by radiogenic isotope ratios of ^(143)Nd/^(144)Nd=0.5125,\n^(87)Sr/^(86)Sr=0.705, ^(206)Pb/^(204)Pb=17.5). Values of \u03b4^(18)O in olivine phenocrysts average 5.21\u00b10.08\u2030\n(n=8). The average \u03b4^(18)O value of 5.21\u00b10.08\u2030 for Pitcairn Island olivine phenocrysts is (1)\nindistinguishable from the average value for olivine from xenoliths of mantle peridotite (5.19\u00b10.14\u2030;\nMattey el al., 1994); (2) similar to the value expected for olivine in the mantle sources of mid-ocean\nridge basalt (i.e., 0.5\u2030 lower than the average for mid-ocean ridge basalt glasses of 5.7\u00b10.2\u2030 (Ito et\nal., 1987) which is the expected fractionation between olivine and basaltic liquid based on\nexperimental and natural studies); and (3) equal to the \u03b4^(18)O value of olivine in lunar basalts (Clayton\net al., 1971). Pitcairn Island lavas and their phenocrysts are therefore close to oxygen isotopic\nequilibrium with the best estimates of olivine in the upper and bulk mantle. Plagioclase \u03b4^(18)O values\naverage 6.05\u00b10.15\u2030 (n=5; 4 from rocks in which olivine was also analyzed), resulting in a\nplagioclase/olivine fractionation close to the expected magmatic value (0.9-1.0\u2030). This indicates that\nolivine and plagioclase were in isotopic equilibrium at magmatic temperatures and therefore suggests\nthat olivine is not exotic to host lavas.", "date": "1995", "date_type": "published", "publication": "Abstracts with Programs - Geological Society of America", "volume": "27", "number": "6", "publisher": "Geological Society of America", "pagerange": "36-36", "id_number": "CaltechAUTHORS:20130809-103916343", "issn": "0016-7592", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130809-103916343", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "resource_type": "article", "pub_year": "1995", "author_list": "Eiler, John M.; Farley, Kenneth; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/07w8y-9cp22", "eprint_id": 35425, "eprint_status": "archive", "datestamp": "2023-08-22 09:55:20", "lastmod": "2023-10-20 16:12:17", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Craig-Harmon", "name": { "family": "Craig", "given": "H." } } ] }, "title": "Atmospheric argon contamination of ocean island basalt olivine phenocrysts", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1994 Elsevier Science Ltd. Received September 7, 1993; accepted in revised form February 1, 1994. We thank R. Comer and V. Craig for their assistance in the field-work on the Juan Fernandez Isiands. We are grateful to Drs. G. B. Dalrymple, M. Harrison, and M. Heizler for their generosity in making the laser-fusion measurements and for\ndiscussions of the methodology. K. Turekian and D. Graham made many helpful suggestions in reviewing the manuscript. This work was supported by National Science Foundation Grants OCE-8720740 and EAR-88 16945 to the Isotope Laboratory, Scripps Institution of Oceanography.\nEditorial handling: K. Marti", "abstract": "^(40)Ar/^(36)Ar and helium and argon concentrations have been repeatedly measured on olivine phenocrysts in a single tholeiitic basalt (PIN-12) from the Juan Fernandez hotspot. Forty olivine splits were analyzed by crushing of bulk samples or laser fusion of single crystals. The measured ^(40)Ar/^(36)Ar ratios span a very large range (400\u20137700) and are consistent with binary mixing of two argon components. Unlike argon, helium in repeated measurements of this single basalt flow has a reproducible isotopic ratio, 17 times the air ^3He/^4He value. It is unlikely that such large variations in ^(40)Ar/^(36)Ar represent microscale mantle heterogeneity. Rather the results indicate highly variable mixing proportions of a mantle-derived radiogenic argon component (^(40)Ar/^(36)Ar > 7700) and an isotopically air-like endmember that is almost certainly an atmospheric contaminant. This air-like constituent cannot be removed by physical and chemical treatments of the olivines.\nAnalysis of individual crystals by laser fusion shows that both the radiogenic and the contaminant components are in fluid inclusions. Siting of the contaminant in inclusions requires the addition of airderived noble gases to hotspot magmas prior to or during emplacement, a process that may occur by assimilation of altered crust during crustal storage or, alternatively, by direct addition of air or seawater to the magma. In either case the olivines must continue to trap argon, presumably by fracture annealing and/or bubble enclosure, after the contaminating event. If atmospheric contamination is a general phenomenon, the ^(40)Ar/^(36)Ar composition of olivines (and possibly of basalt glasses as well) must be only a lower limit for the mantle source ratio. With the exception of helium, the other noble gases may be similarly compromised. Our results support contentions that lavas with near-atmospheric noble gas compositions reflect severe atmospheric contamination, rather than the air-like signature of an undegassed primitive mantle reservoir.", "date": "1994-06", "date_type": "published", "publication": "Geochimica et Cosmochimica Acta", "volume": "58", "number": "11", "publisher": "Elsevier", "pagerange": "2509-2517", "id_number": "CaltechAUTHORS:20121113-105804078", "issn": "0016-7037", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121113-105804078", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OCE-8720740" }, { "agency": "NSF", "grant_number": "EAR-8816945" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/0016-7037(94)90027-2", "resource_type": "article", "pub_year": "1994", "author_list": "Farley, K. A. and Craig, H." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/9w4zb-5g284", "eprint_id": 35373, "eprint_status": "archive", "datestamp": "2023-08-22 09:40:49", "lastmod": "2023-10-20 16:09:24", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Torgerson-T", "name": { "family": "Torgerson", "given": "T." } }, { "id": "Drenkard-S", "name": { "family": "Drenkard", "given": "S." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K." }, "orcid": "0000-0002-7846-7546" }, { "id": "Schlosser-P", "name": { "family": "Schlosser", "given": "P." } }, { "id": "Shapiro-A", "name": { "family": "Shapiro", "given": "A." } } ] }, "title": "Mantle helium in groundwater of the Mirror Lake Basin, New Hampshire, USA", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1994 by Terra Scientific Publishing Company.\n\nLamont Dhoerty Earth Observatory contribution number 5273. This\nwork was supported in part by the US Geological Survey and The Institute of Water\nResources at the University of Connecticut. S. Drenkard was supported by the German\nScience Foundation (DFG #277).", "abstract": "Helium isotope analyses of ground waters from the Mirror Lake drainage basin in\ncentral New Hampshire (USA) show helium in excess of air-saturated water by up to 200x.\nThe freon ages of these waters are younger than 50 years, consistent with the local hydrology.\nThis excess helium has an isotope ratio of ^3He/^4He = 1.65 \u00b1 0.10 x 10^(-6). It is shown that this\ncomponent cannot be the result of cosmogenic production or mixing with young water\ncontaining ^3He from the decay of (bomb) tritium. Measurements of the helium isotope ratio\nof local rocks indicate that they cannot be the source of this excess component. This strongly\nsuggests that the excess helium component is the result of the addition of some external\nsource of mantle helium. The generally accepted view suggests that mantle helium in\ncontinental environments is the result of active volcanism and extensional tectonics. The\nlatest episodes of volcanism in this region of New England are related to the New England\nhot spot track (95-190 Myr) and the closure of the Iapetus (> 300 Myr). Thus, either the\ntimescale for helium transport through the crust is of the order of 100's of Myr or the\nsignature of mantle helium can be preserved in (e.g.) fluid inclusions for significant periods\nof time.", "date": "1994", "date_type": "published", "publisher": "Terra Scientific Publishing Company", "place_of_pub": "Tokyo", "pagerange": "279-292", "id_number": "CaltechAUTHORS:20121108-153915641", "isbn": "9784887041141", "book_title": "Noble Gas Geochemistry and Cosmochemistry", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121108-153915641", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS" }, { "agency": "University of Connecticut Institute of Water Resources" }, { "agency": "German Science Foundation (DFG)", "grant_number": "277" } ] }, "other_numbering_system": { "items": [ { "id": "5273", "name": "Lamont Dhoerty Earth Observatory" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Matsuda-J", "name": { "family": "Matsuda", "given": "J." } } ] }, "resource_type": "book_section", "pub_year": "1994", "author_list": "Torgerson, T.; Drenkard, S.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/5p3wx-mat28", "eprint_id": 35372, "eprint_status": "archive", "datestamp": "2023-08-22 09:40:41", "lastmod": "2023-10-20 16:09:22", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Poreda-R-J", "name": { "family": "Poreda", "given": "R. J." } }, { "id": "Onstott-T-C", "name": { "family": "Onstott", "given": "T. C." } } ] }, "title": "Noble gases in deformed xenoliths from an ocean island: characterization of a metasomatic fluid", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1994 by Terra Scientific Publishing Company.\n\nWe thank James H. Natland for supplying the samples and for\nproviding insights to their composition and origin and the Yamada Foundation for their\nfinancial support of the Noble Gas Conference. Discussions with Julie Dieu and comments\nfrom an anonymous reviewer were helpful. This work was supported by the NSF (EAR 92-04822).", "abstract": "New noble gas measurements have been made on Samoan ultramafic xenoliths\nin order to characterize the composition and nature of entrapment of a postulated mantle\nmetasomatic agent. The new measurements were performed on gases extracted from\nseverely tectonized harzburgites and dunites by both bulk crushing and laser microprobe.\nThe tectonized specimens have the highest noble gas concentrations yet reported from\nmantle materials and attest to deformation in a highly gas-charged environment. The noble\ngas isotopic systematics are similar to those observed in undeformed specimens from the\nsame locality, and are consistent with mixing between a mantle component (e.g. ^3He/^4He =\n12 R_A, ^(40)Ar/^(36) Ar > 10,000) and an atmospheric contaminant. Within the xenoliths, the\nmantle component is spatially associated with features previously attributed to metasomatism\n(e.g. HAURI et al., 1993). Although this metasomatic component has many characteristics\nsuggesting derivation from material returned to the mantle by subduction, its relatively high\n^3He/^4He ratio is enigmatic. Whatever its source, this fluid appears to have existed within the\nSamoan mantle over fairy large temporal and spatial scales, and plays an important role in\nthe geochemistry of Samoan basalts.\nJust as with the mantle component, the deformed xenoliths are also enriched in the\natmospheric contaminant. This enrichment suggests pervasive penetration of air into the\nubiquitous micro fractures and decrepitated fluid inclusions of the deformed specimens.\nIn addition to source and contamination effects, the noble gases within these xenoliths\nrecord variable degrees of elemental fractionation. While the gas-rich (deformed) xenoliths\nhave ^4He-^(21)Ne*-^(40)Ar* systematics close to long-term closed-system behavior, the comparatively\ngas-poor samples have lost up to 90% of their helium without concomitant loss of neon\nand argon. This likely represents diffusive loss of helium after fluid inclusion entrapment.", "date": "1994", "date_type": "published", "publisher": "Terra Scientific Publishing Company", "place_of_pub": "Tokyo", "pagerange": "159-178", "id_number": "CaltechAUTHORS:20121108-152313030", "isbn": "9784887041141", "book_title": "Noble Gas Geochemistry and Cosmochemistry", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121108-152313030", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Yamada Foundation" }, { "agency": "NSF", "grant_number": "EAR 92-04822" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Matsuda-J", "name": { "family": "Matsuda", "given": "J." } } ] }, "resource_type": "book_section", "pub_year": "1994", "author_list": "Farley, K. A.; Poreda, R. J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ce53w-s6t63", "eprint_id": 42139, "eprint_status": "archive", "datestamp": "2023-08-22 09:34:40", "lastmod": "2023-10-25 15:41:09", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Basu-A-R", "name": { "family": "Basu", "given": "A. R." } }, { "id": "Craig-Harmon", "name": { "family": "Craig", "given": "H." } } ] }, "title": "He, Sr and Nd isotopic variations in lavas from the Juan Fernandez Archipelago, SE Pacific", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1993 Springer-Verlag.\nReceived October 5, 1992; Accepted April 5, 1993.\n\nWe thank H. Vergara for supplying two samples\nfrom Mas a Tierra and J. Clark for participating in the field\nwork. Dr. J.D. Macdougall generously provided access to the SIO\nthermal ionization mass spectrometry facilities. J Hawkins and\ncompany guided the XRF work. Ev Hernandez maintained the\nmass spectrometry facilities with his usual skill. We thank Dave\nGraham, Mark Kurz, and Kristen Nilsson for helpful reviews. This\nwork was supported by NSF grants to H. Craig.", "abstract": "Helium, Sr, and Nd isotopic ratios and major and trace element compositions have been measured on a suite of lavas from the intra-plate volcanos of the Juan Fernandez Archipelago, Chile. Lavas from the islands of Mas Afuera and Mas a Tierra and from Monte Alpha and Friday seamounts have Sr and Nd isotopic ratios lying on the low ^(143)Nd/^(144)Nd side of the mantle array (^(87)Sr/^(86)Sr:0.7034\u20130.7037; ^(143)Nd/^(144)Nd:0.51281\u20130.51289). The homogeneity of these tracers suggests the involvement of a restricted range of mantle source compositions throughout Juan Fernandez volcanism. In marked contrast is the large range in ^3He/^4He, from 7.8 to 18.0 R_A. A bimodal ^3He/^4He distribution on Mas a Tierra is associated with two distinct volcanic lineages; ^3He/^4He ratios of 14.5\u201318.0 R_A (n=15) occur in alkalic and tholeiitic shield basalts, whereas post-shield basanites range from 11.2 to 13.6 R_A (n=12). Elemental and isotopic systematics demonstrate a transition from an enriched (Loihi-like) plume source in the shield lavas to a more MORB-like source in the post-shield volcanics. The transition between these sources is much more pronounced in ^3He/^4He than in the other isotopic tracers. The predominantly tholeiitic basalts of Mas Afuera have exceptionally uniform isotopic and elemental characteristics; Sr and Nd ratios are similar to those of Mas a Tierra, but ^3He/^4He ratios are lower and more uniform at 8.3\u00b10.5 R_A (n=17). The dramatic distinction between Mas Afuera and Mas a Tierra helium is surprising given the great similarity between the two islands in other geochemical characteristics. Both the Mas Afuera and Mas a Tierra results demonstrate that helium records systematic processes not readily apparent from other isotopic or elemental indicators. Neither magma chamber degassing nor local metasomatic events are likely to be responsible. We suggest that the observed variations may be attributed to mixing of plume and asthenospheric sources in which the plume component is characterized by a heterogeneous distribution of volatiles or has suffered extraction of small degree partial melts prior to mixing.", "date": "1993-10", "date_type": "published", "publication": "Contributions to Mineralogy and Petrology", "volume": "115", "number": "1", "publisher": "Springer", "pagerange": "75-87", "id_number": "CaltechAUTHORS:20131030-111746698", "issn": "0010-7999", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131030-111746698", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1007/BF00712980", "resource_type": "article", "pub_year": "1993", "author_list": "Farley, K. A.; Basu, A. R.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/5tdmg-mdr16", "eprint_id": 38300, "eprint_status": "archive", "datestamp": "2023-08-20 02:56:18", "lastmod": "2023-10-23 20:01:42", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Is \"Primordial\" Helium Really Extraterrestrial?", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1993 American Association for the Advancement of Science.", "abstract": "Among the isotope systems exploited by mantle geochemists to deduce the chemical evolution of the Earth, those of the rare gases are unique because they record the migration of volatile species from the mantle to the atmosphere. The isotopic composition of helium in mantle-derived rocks is now reasonably well known, and it suggests that this migration has been both more heterogeneous and less extensive than commonly expected. The implications of the helium data are profound, but they seem to conflict with widely held beliefs derived from other geochemical tracers, including the isotopic characteristics of lithophile elements (that is, elements such as Sr, Nd, and Pb found predominantly in Earth's silicate rust). Although the geochemical processes affecting the rare gases and lithophile species must be intimately related, it has proven difficult to reconcile them in any obvious way. On page 170 of this issue, Anderson offers a controversial hypothesis that can simultaneously explain all of these disparate tracers (1). If he is correct, a dramatic reinterpretation of the terrestrial rare gas data and their significance to planetary evolution is required.", "date": "1993-07-09", "date_type": "published", "publication": "Science", "volume": "261", "number": "5118", "publisher": "American Association for the Advancement of Science", "pagerange": "166-167", "id_number": "CaltechAUTHORS:20130506-150523245", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130506-150523245", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.261.5118.166", "resource_type": "article", "pub_year": "1993", "author_list": "Farley, K. A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ynbss-x8038", "eprint_id": 35424, "eprint_status": "archive", "datestamp": "2023-08-22 09:11:32", "lastmod": "2023-10-20 16:12:14", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Poreda-R-J", "name": { "family": "Poreda", "given": "R. J." } } ] }, "title": "Mantle neon and atmospheric contamination", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1993 Elsevier Science Publishers B.V. Received June 29, 1992; revision accepted November 20, 1992. We thank T. Trull and M. Honda for helpful reviews. This work was supported by NSF grants EAR-9204822 and EAR-9105032.", "abstract": "The apparent distinction between atmospheric and mantle ^(20)Ne/^(22)Ne ratios may provide a technique to quantify air contamination in mantle-derived materials. In the absence of mantle nuclear reactions, which produce either ^(20)Ne or ^(22)Ne in substantial quantities, it is likely that the entire mantle is characterized by a single, uniform ^(20)Ne/^(22)Ne ratio; a value of around 12.5 is suggested by analyses of MORBs, OIBs, diamonds and xenoliths. If this premise is correct, then any measured ^(20)Ne/^(22)Ne ratios in mantle samples that are lower than this must result from addition of an air component, with ^(20)Ne/^(22)Ne= 9.8. This is most likely a syn- or post-eruptive contaminant. The degree of air contamination inferred from ^(20)Ne/^(22)Ne ratios is generally small for diamonds, but is increasingly significant for MORBs and OIBs; many OIB's may carry > 90% air neon. We calculated \"air-neon corrected\" ^(21)Ne/^(22)Ne and ^(40)Ar/^(36)Ar ratios for the highly degassed MORB mantle and for the less degassed (high ^3He/^4He) \"plume\" reservoir. The inferred MORB composition is indistinguishable from measurements of some gas-rich glasses. The calculated plume composition is similar to the least air-like measurements from ocean islands, but is less air-like than has been proposed previously. This plume composition is not consistent with a completely undegassed reservoir.\nFrom these corrected mantle compositions, we calculated the relative time-integrated rare gas abundances in the mantle, using a simple evolutionary model, which simultaneously considers the isotopic compositions of He, Ne, Ar and Xe. The model shows that both MORB and plume reservoirs have evolved with nearly solar elemental abundances. This provides strong support to suggestions based on Ne isotopes that the Earth accreted with gases nearly solar in composition. Importantly, the inferred mantle Ne/Ar ratios are much higher than atmospheric, which is consistent with simultaneous fractionation of both the atmospheric neon isotope ratio and the Ne/Ar ratio by massive hydrodynamic escape. Mixing between MORB and plume reservoirs (with our calculated elemental and isotopic abundances), plus varying amounts of added air, can account for the rare gases in nearly all mantle-derived rocks.", "date": "1993-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "114", "number": "2-3", "publisher": "Elsevier", "pagerange": "325-339", "id_number": "CaltechAUTHORS:20121113-103255415", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121113-103255415", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9204822" }, { "agency": "NSF", "grant_number": "EAR-9105032" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/0012-821X(93)90034-7", "resource_type": "article", "pub_year": "1993", "author_list": "Farley, K. A. and Poreda, R. J." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/cp9a7-qbf46", "eprint_id": 39137, "eprint_status": "archive", "datestamp": "2023-08-22 09:03:18", "lastmod": "2023-10-24 16:27:45", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Craig-Harmon", "name": { "family": "Craig", "given": "H." } } ] }, "title": "Mantle Plumes and Mantle Sources", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1992 American Association for the Advancement of Science.\n\nReceived 1 June 1992; accepted 17 August 1992.", "abstract": "Basalts from many ocean islands define elongate arrays in Sr-Nd-Pb isotopic space; these likely reflect the dominance of binary mixing of mantle sources in intraplate volcanism. S. R. Hart et al. (1) observe that when these arrays are projected onto a ternary diagram bounded by mantle end-members DMM [depleted mid-ocean ridge basalt (MORB) mantle], HIMU (high U/Pb mantle), and EMI (enriched mantle 1), they are subparallel and point toward a composition on the DMM-HIMU join. Hart et al. suggest this composition is associated with a high ^3He/^4He ratio (>30 R_A) and therefore cannot be a ubiquitous upper-mantle mixture of DMM and HIMU (both of which have ^3He/^4He < 9 R_A). They instead argue in favor of a new isotopic component, resident in a deep mantle \"Focus Zone\" (FOZO), which is characterized by a high ^3He/^4He ratio or which acquires helium with a high ^3He/^4He signature from the core.", "date": "1992-10-30", "date_type": "published", "publication": "Science", "volume": "258", "number": "5083", "publisher": "American Association for the Advancement of Science", "pagerange": "821-821", "id_number": "CaltechAUTHORS:20130628-094256518", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130628-094256518", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "resource_type": "article", "pub_year": "1992", "author_list": "Farley, K. A. and Craig, H." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/9v8nq-n9c55", "eprint_id": 35423, "eprint_status": "archive", "datestamp": "2023-08-22 08:57:59", "lastmod": "2023-10-20 16:12:09", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Poreda-R-J", "name": { "family": "Poreda", "given": "R. J." } }, { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" } ] }, "title": "Rare gases in Samoan xenoliths", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1992 Elsevier Science Publishers B.V. Received February 24, 1992; revision accepted July 13, 1992. The authors wish to thank J. Natland and J. Hawkins for providing the xenoliths and for useful discussions. Reviews by D. Fisher, D. Graham and Ph. Sarda improved the quality of the\nmanuscript. This work was funded by the Petrology and Geochemistry Program, Earth Sciences Division, NSF, EAR 9105032 to RJP at the University of Rochester.", "abstract": "The rare gas isotopic compositions of residual harzburgite xenoliths from Savai'i (SAV locality) and an unnamed seamount south of the Samoan chain (PPT locality) provide important constraints on the rare gas evolution of the mantle and atmosphere. Despite heterogeneous trace element compositions, the rare gas characteristics of the xenoliths from each of the two localities are strikingly similar. SAV and PPT xenoliths have ^3He/^4He ratios of 11.1 \u00b1 0.5 R_A and 21.6 \u00b1 1 R_A, respectively; this range is comparable to the ^3He/^4He ratios in Samoan lavas and clearly demonstrates that they have trapped gases from a relatively undegassed reservoir. The neon results are not consistent with mixing between MORB and a plume source with an atmospheric signature. Rather, the neon isotopes reflect either a variably degassed mantle (with a relative order of degassing of Loihi < PPT < Reunion < SAV < MORB), or mixing between the Loihi source and MORB. The data supports the conclusions of Honda et al. that the ^(20)Ne/^(22)Ne ratio in the mantle more closely resembles the solar ratio than the atmospheric one. ^(40)Ar/^(36)Ar ratios in the least contaminated samples range from 4,000 to 12,000 with the highest values in the 22 R_A PPT xenoliths. There is no evidence for atmospheric ^(40)Ar/^(36)Ar ratios in the mantle source of these samples, which indicates that the lower mantle may have ^(40)Ar/^(36)Ar ratios in excess of 5,000. Xenon isotopic anomalies in ^(129)Xe and ^(136)Xe are as high as 6%, or about half of the maximum MORB excess and are consistent with the less degassed nature of the Samoan mantle source. These results contradict previous suggestions that the high ^3He/^4He mantle has a near-atmospheric heavy rare gas isotopic composition.", "date": "1992-09", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "113", "number": "1-2", "publisher": "Elsevier", "pagerange": "129-144", "id_number": "CaltechAUTHORS:20121113-101918346", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121113-101918346", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR 9105032" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/0012-821X(92)90215-H", "resource_type": "article", "pub_year": "1992", "author_list": "Poreda, R. J. and Farley, K. A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/8n3x0-egm26", "eprint_id": 35422, "eprint_status": "archive", "datestamp": "2023-08-22 08:51:21", "lastmod": "2023-10-20 16:12:03", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Natland-J-H", "name": { "family": "Natland", "given": "J. H." } }, { "id": "Craig-Harmon", "name": { "family": "Craig", "given": "H." } } ] }, "title": "Binary mixing of enriched and undegassed (primitive?) mantle\n components (He, Sr, Nd, Pb) in Samoan lavas", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1992 Elsevier Science Publishers B.V. Received November 20, 1991; revision accepted April 20, 1992. We thank D. Macdougall for the use of his laboratory and for helpful assistance and discussion, G. Lugmair for analytical skills and discussion, E. Hernandez and H. Kueker for maintaining\nthe isotope laboratory, V. Craig for material assistance, and L. Garwin for redirection of the manuscript. S. Hart, J.-G. Schilling, and D. Graham improved the paper significantly and we are grateful for their efforts. This work was supported by NSF grants EAR88-16954 and\nOCE87-22810 to H. Craig and EAR87-10858 to D. Macdougall.", "abstract": "We have measured He, Sr, Nd, and Pb isotope ratios and Rb, Sr, Sm, and Nd concentrations in stratigraphically controlled lavas from the Pago shield volcano on Tutuila, American Samoa. We interpret these lavas as products of mixing between two isotopically extreme mantle constituents. The first is a highly enriched component with very high Sr isotope ratios, low ^3He/^4He ratios, and high \"\u0394(7/4)\" and \"\u0394(8/4)\" Pb isotopic characteristics. This is probably recently recycled ( < 400 Ma) crustal material. The second component has high ^3He/^4He ratios ( > 24R_A) and intermediate Sr, Nd, and Pb isotopic ratios. This material was derived from a largely undegassed mantle source, and, in conjunction with data from several other ocean islands, provides strong evidence for the existence of a high ^3He/^4He ratio mantle end member (primitive helium mantle, PHEM) with consistent Sr, Nd, and Pb isotopic characteristics: near bulk-earth ^(87)Sr/^(86)Sr (0.7042\u20130.7052) and ^(143)Nd/^(144)Nd (0.51265\u20130.51280,\u03b5_(Nd) = +0.2to+3.2), and radiogenic Pb (^(206)Pb/^(204)Pb\u223c 18.5\u201319.0, ^(207)Pb/^(204)Pb\u223c 15.5\u201315.57, ^(208)Pb/^(204)Pb\u223c 38.4\u201339.2). Although this material cannot have been derived from a reservoir completely closed to elemental fractionation for the full 4.55 Ga duration of Earth's history, it may indicate the presence of a highly primitive mantle source.\nErratic temporal variations in the isotopic composition of individual flows indicate sporadic and variable mixing of these two sources. We interpret these results using a model in which high ^3He/^4He ratio plume material, rising intermittently from a lower-mantle source, intercepts and melts recycled crustal matter in the upper mantle or lithosphere and erupts as a binary mixture of PHEM and the so-called \"EM\" components derived from this recycled material.", "date": "1992-06", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "111", "number": "1", "publisher": "Elsevier", "pagerange": "183-199", "id_number": "CaltechAUTHORS:20121113-100449047", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121113-100449047", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR88-16954" }, { "agency": "NSF", "grant_number": "OCE87-22810" }, { "agency": "NSF", "grant_number": "EAR87-10858" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/0012-821X(92)90178-X", "resource_type": "article", "pub_year": "1992", "author_list": "Farley, K. A.; Natland, J. H.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/q6phe-y0m96", "eprint_id": 35427, "eprint_status": "archive", "datestamp": "2023-08-22 07:50:05", "lastmod": "2023-10-20 16:12:25", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farley-K-A", "name": { "family": "Farley", "given": "K. A." }, "orcid": "0000-0002-7846-7546" }, { "id": "Turekian-K-K", "name": { "family": "Turekian", "given": "K. K." } } ] }, "title": "Lead-210 in the circumpolar South Atlantic", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1990 Pergamon Press. Received 19 January 1990; in revised form 16 July 1990; accepted 31 July 1990. Glen Shen and other members of the Ajax expedition carefully sampled the water into our acidified bottles and guaranteed transfer to us. H. Craig provided helpful comments on the manuscript. This research was supported by DOE grant no. DE-FGO2-87ER60595.", "abstract": "^(210)Pb activity in circumpolar waters of the South Atlantic is characterized by a sharply defined maximum at intermediate to shallow depths that is strongly correlated with the oxygen minimum. This feature, present throughout the Southern Ocean, is most likely locally maintained rather than advected from elsewhere. The highest ^(210)Pb activities in this region occur in the northern Weddell Sea, indicating a source of ^(210)Pb-rich water in the west or north flank of the Weddell Sea Gyre. An estimate of the (^(210)Pb) deficiency relative to (^(226)Ra) shows that despite high biological productivity, the sediments underlying the Southern Ocean are not a major sink for ^(210)Pb.", "date": "1990-12", "date_type": "published", "publication": "Deep Sea Research Part A", "volume": "37", "number": "12", "publisher": "Elsevier", "pagerange": "1849-1860", "id_number": "CaltechAUTHORS:20121113-111130095", "issn": "0198-0149", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121113-111130095", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "DE-FGO2-87ER60595" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/0198-0149(90)90081-6", "resource_type": "article", "pub_year": "1990", "author_list": "Farley, K. A. and Turekian, K. K." } ]