[ { "id": "https://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.edu/records/0enh1-yhf03", "eprint_id": 65850, "eprint_status": "archive", "datestamp": "2023-08-22 17:28:35", "lastmod": "2023-10-18 16:51:48", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Douglas-P-M-J", "name": { "family": "Douglas", "given": "Peter" } }, { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "John" } }, { "id": "Stolper-D-A", "name": { "family": "Stolper", "given": "Daniel" }, "orcid": "0000-0003-3299-3177" }, { "id": "Smith-D", "name": { "family": "Smith", "given": "Derek" } }, { "id": "Walter-Anthony-K", "name": { "family": "Walter Anthony", "given": "Katey" } }, { "id": "Paull-C", "name": { "family": "Paull", "given": "Charlie" } }, { "id": "Dallimore-S", "name": { "family": "Dallimore", "given": "Scott" } }, { "id": "Wik-M", "name": { "family": "Wik", "given": "Martin" } }, { "id": "Crill-P", "name": { "family": "Crill", "given": "Patrick" } }, { "id": "Winterdahl-M", "name": { "family": "Winterdahl", "given": "Mattias" } } ] }, "title": "Diverse origins of Arctic and subarctic methane point source emissions identified with multiply substituted isotopologues", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2016 American Chemical Society.", "abstract": "Methane is a potent greenhouse gas, and there are concerns that its natural emissions from the Arctic could\nact as a substantial pos. feedback to anthropogenic global warming. Detg. the sources of methane and the\nbiogeochem. processes controlling them is important for understanding present and future Arctic emissions.\nHere we apply multiply substituted isotopologues, or clumped isotopes, of methane as a new tool to identify\nthe origins of ebullitive fluxes in Alaska, Sweden and the Arctic Ocean. When methane forms in isotopic\nequil., clumped isotope measurements indicate the formation temp. In some microbial methane, however,\nnon-equil. isotope effects, which are probably related to the kinetics of methanogenesis, lead to low proportions\nof clumped isotopes. We identify four categories of emissions in the studied samples: thermogenic methane,\ndeep subsurface or marine microbial methane formed in isotopic equil., freshwater microbial methane with\nnon-equil. clumped isotope values, and mixts. of microbial and thermogenic methane (i.e., combinations of the\nfirst three end members). Mixing between thermogenic and microbial methane produces a non-linear variation\nin clumped isotope values with mixing proportion that provides new constraints for the formation environment of\nthe mixing end-members. Analyses of microbial methane emitted from lakes, as well as a methanol-consuming\nmethanogen pure culture, support the hypothesis that non-equil. clumped isotope values are controlled, at least\nin part, by kinetic isotope effects related to the reversibility of the enzymic reactions involved in\nmethanogenesis. In addn., we observe a pos. correlation between clumped isotope values and flux in lacustrine\nmicrobial methane samples, suggesting a link between the kinetics of methanogenesis and the rate of\nemissions from lakes.", "date": "2016-03", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20160401-110926549", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160401-110926549", "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": "conference_item", "pub_year": "2016", "author_list": "Douglas, Peter; Eiler, John; et el." }, { "id": "https://authors.library.caltech.edu/records/8p0er-bw772", "eprint_id": 66131, "eprint_status": "archive", "datestamp": "2023-08-22 17:29:03", "lastmod": "2023-10-18 17:10:58", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "John" } } ] }, "title": "Rolling revolution in analytical isotope geochemistry", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2016 American Chemical Society.", "abstract": "The many subjects of isotope geochem. have two things in common: they generally require anal. of isotope ratios at low\nnatural abundances (\u223c10^(-2)-10^(-6)) and high precision (\u223c10^(-3)-10(-6)). For the first 50 years of this field (ca. 1950-2000), these\nrequirements were met by a narrow range of technologies - mostly low mass resoln. (M/\u0394M of a few hundred) TIMS and gas\nsource IRMS - that limited the field to a few simple mols. and elements. Over the last 15 years this field has been transformed\nby the emergence of a wide range of new instruments and methods: plasma-source, high-resoln. MC-ICPMS has dramatically\nexpanded the list of easily analyzed elements, and, a variety of technologies have opened up the world of mol. isotopic\nstructure (site specific effects and multiple substitutions), including: high-precision, natural-abundance NMR; GC-pyrolysis-GCIRMS\nexpts.; IR absorption spectroscopy; and high- sensitivity, high-mass-resoln. gas source IRMS. These technologies\ngenerally complement one another rather than competing directly, and are collectively supporting a revolution in the way in\nwhich mol. isotopic structure is used to create novel geochem. tools - high- dimensionality forensic fingerprints; highly specific\nmetabolic signatures; thermometers based on intramol. isotopic distributions. The pace of this work has accelerated\ndramatically in the last \u223c5 years, and is likely to expand further in coming years with the introduction of instruments having\ndistinctive capabilities and no prior history of use in this field (e.g., terahertz spectroscopy; Fourier-transform mass\nspectrometry).", "date": "2016-03", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20160413-142601846", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160413-142601846", "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": "conference_item", "pub_year": "2016", "author_list": "Eiler, John" }, { "id": "https://authors.library.caltech.edu/records/e7cgf-0nj40", "eprint_id": 39921, "eprint_status": "archive", "datestamp": "2023-08-22 05:23:27", "lastmod": "2023-10-24 17:18:58", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Snell-K-E", "name": { "family": "Snell", "given": "Kathryn E." } }, { "id": "Eiler-J-M", "name": { "family": "Eiler", "given": "John M." } }, { "id": "Dettman-D-L", "name": { "family": "Dettman", "given": "David L." } }, { "id": "Grotzinger-J-P", "name": { "family": "Grotzinger", "given": "John P." }, "orcid": "0000-0001-9324-1257" }, { "id": "Koch-P-L", "name": { "family": "Koch", "given": "Paul L." } } ] }, "title": "Evaluating the Geochemical Consequences of Aragonite-to-Aragonite Diagenesis in Freshwater Fossil Bivalves", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 AAPG.\n\nAAPG Search and Discovery Article #90142.", "abstract": "Carbonate clumped isotope (\u0394_(47)) thermometry provides an independent test of the metrics used to assess the preservation of carbonate rocks and fossils. Additionally, \u0394_(47) thermometry, when combined with other geochemical and structural measurements, may establish whether diagenesis occurred under closed-system conditions, open-system conditions, or some combination thereof. Here we present an example of diagenesis of Eocene-aged freshwater mollusk fossils (Unionidae) from Wyoming. The fossils yielded \u0394_(47) temperatures from 41-46\u00b0C, which is physiologically unreasonable. However, X-Ray diffraction (XRD) data indicate that all but one of the fossils contain only aragonite \u2014 the carbonate phase unionids deposit; one sample contained small amounts of calcite in powder XRD analysis. We used scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), cathodoluminescence (CL) and secondary electron mass spectrometry (SIMS) of polished thin sections and etched fragments to describe the detailed textural, mineralogical, and trace element characteristics of two of these fossils and one modern unionid shell.", "date": "2012-04", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20130814-153842490", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130814-153842490", "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": "conference_item", "pub_year": "2012", "author_list": "Snell, Kathryn E.; Eiler, John M.; et el." }, { "id": "https://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." } ]