[ { "id": "authors:59g8g-m6058", "collection": "authors", "collection_id": "59g8g-m6058", "cite_using_url": "https://authors.library.caltech.edu/records/59g8g-m6058", "type": "book_section", "title": "Data report: petrography of volcaniclastic intervals in IODP Expedition 385 cores from Guaymas Basin, Gulf of California", "author": [ { "family_name": "Martinez", "given_name": "Priscilla R.", "orcid": "0000-0001-7294-9467" }, { "family_name": "Marsaglia", "given_name": "Kathleen M.", "orcid": "0000-0001-5430-4630" }, { "family_name": "Stock", "given_name": "Joann M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" } ], "abstract": "

The Guaymas Basin is a 6 Ma transtensional ocean basin located in the central Gulf of California characterized by active seafloor spreading, off-axis magmatism, and high biogenic and terrigenous sedimentation rates. Sparse volcaniclastic intervals were identified by shipboard scientists in Quaternary sedimentary cores recovered during International Ocean Discovery Program (IODP) Expedition 385. Shipboard visual core descriptions and smear slide analyses were used to identify 57 volcaniclastic intervals, which were then sampled and analyzed macroscopically and microscopically. Petrographic modal analyses were conducted on a subset of 36 thin sections with a total of 300 points counted per thin section. A grain classification scheme was developed from published literature to characterize the compositional and textural variability of volcanic grains in cores from across the basin. Point count percentages reveal that vitric volcanic lithic fragments, particularly brown glass shards, are the dominant clast type observed at all drill sites, whereas crystal-bearing volcanic lithic fragments and mineral grains comprise a minor percentage of the total points counted. The vitric fragments also exhibit a wide range of shard vesicularity and morphologies. This data report presents a petrographic analysis of volcaniclastic deposits recovered during Expedition 385 to elucidate on the modal and spatial distribution of volcanic material in the Guaymas Basin.

", "doi": "10.14379/iodp.proc.385.206.2025", "issn": "2377-3189", "publisher": "International Ocean Discovery Program", "publication": "Proceedings of the International Ocean Discovery Program", "publication_date": "2025-01-10", "volume": "385" }, { "id": "authors:1f1gb-hp882", "collection": "authors", "collection_id": "1f1gb-hp882", "cite_using_url": "https://authors.library.caltech.edu/records/1f1gb-hp882", "type": "book_section", "title": "Expedition 385 methods", "author": [ { "family_name": "Teske", "given_name": "A.", "orcid": "0000-0003-3669-5425" }, { "family_name": "Lizarralde", "given_name": "D.", "orcid": "0000-0001-6152-6039" }, { "family_name": "H\u00f6fig", "given_name": "T.W.", "orcid": "0000-0002-9254-4528" }, { "family_name": "Aiello", "given_name": "I.W.", "orcid": "0000-0001-9794-6852" }, { "family_name": "Ash", "given_name": "J.L.", "orcid": "0000-0003-4062-3942" }, { "family_name": "Bojanova", "given_name": "D.P.", "orcid": "0000-0001-7787-6682" }, { "family_name": "Buatier", "given_name": "M.D.", "orcid": "0000-0003-3863-5127" }, { "family_name": "Edgcomb", "given_name": "V.P.", "orcid": "0000-0001-6805-381X" }, { "family_name": "Galerne", "given_name": "C.Y.", "orcid": "0000-0001-9696-205X" }, { "family_name": "Gontharet", "given_name": "S.", "orcid": "0000-0002-8624-2654" }, { "family_name": "Heuer", "given_name": "V.B.", "orcid": "0000-0002-1856-116X" }, { "family_name": "Jiang", "given_name": "S.", "orcid": "0000-0001-6259-7912" }, { "family_name": "Kars", "given_name": "M.A.C.", "orcid": "0000-0002-4984-1412" }, { "family_name": "Khogenkumar Singh", "given_name": "S.", "orcid": "0000-0003-4536-3158" }, { "family_name": "Kim", "given_name": "J.", "orcid": "0000-0003-2430-3869" }, { "family_name": "Koornneef", "given_name": "L.M.T.", "orcid": "0000-0002-8016-1167" }, { "family_name": "Marsaglia", "given_name": "K.M.", "orcid": "0000-0001-5430-4630" }, { "family_name": "Meyer", "given_name": "N.R.", "orcid": "0000-0001-5436-1117" }, { "family_name": "Morono", "given_name": "Y.", "orcid": "0000-0001-8928-4254" }, { "family_name": "Negrete-Aranda", "given_name": "R.", "orcid": "0000-0003-3049-4374" }, { "family_name": "Neumann", "given_name": "F.", "orcid": "0000-0002-9666-5087" }, { "family_name": "Pastor", "given_name": "L.C.", "orcid": "0000-0001-9732-8907" }, { "family_name": "Pe\u00f1a-Salinas", "given_name": "M.E.", "orcid": "0000-0002-5835-0455" }, { "family_name": "P\u00e9rez Cruz", "given_name": "L.L." }, { "family_name": "Ran", "given_name": "L.", "orcid": "0000-0002-5198-2628" }, { "family_name": "Riboulleau", "given_name": "A.", "orcid": "0000-0002-2717-8330" }, { "family_name": "Sarao", "given_name": "J.A.", "orcid": "0000-0002-2014-1156" }, { "family_name": "Schubert", "given_name": "F.", "orcid": "0000-0002-1618-3978" }, { "family_name": "Stock", "given_name": "J.M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Toffin", "given_name": "L.M.A.A.", "orcid": "0000-0003-0012-1833" }, { "family_name": "Xie", "given_name": "W.", "orcid": "0000-0002-9742-9369" }, { "family_name": "Yamanaka", "given_name": "T.", "orcid": "0000-0002-6807-6904" }, { "family_name": "Zhuang", "given_name": "G.", "orcid": "0000-0002-6282-8415" } ], "abstract": "

This chapter outlines the procedures and methods employed for coring and drilling operations as well as in the various shipboard laboratories of the research vessel (R/V) JOIDES Resolution during International Ocean Discovery Program (IODP) Expedition 385. The laboratory information applies only to shipboard work described in the Expedition Reports section of the Expedition 385 Proceedings of the International Ocean Discovery Program volume, using the shipboard sample registry, imaging and analytical instruments, core description tools, and the Laboratory Information Management System (LIMS) database. Methods used by investigators for shore-based analyses of Expedition 385 samples and data will be described in separate individual peer-reviewed scientific publications.

", "doi": "10.14379/iodp.proc.385.102.2021", "issn": "2377-3189", "isbn": "978-1-954252-77-6", "publisher": "International Ocean Discovery Program", "publication": "Proceedings of the International Ocean Discovery Program", "publication_date": "2021-09-27" }, { "id": "authors:y1776-0sn27", "collection": "authors", "collection_id": "y1776-0sn27", "cite_using_url": "https://authors.library.caltech.edu/records/y1776-0sn27", "type": "book_section", "title": "Expedition 385 summary", "author": [ { "family_name": "Teske", "given_name": "A.", "orcid": "0000-0003-3669-5425" }, { "family_name": "Lizarralde", "given_name": "D.", "orcid": "0000-0001-6152-6039" }, { "family_name": "H\u00f6fig", "given_name": "T.W.", "orcid": "0000-0002-9254-4528" }, { "family_name": "Aiello", "given_name": "I.W.", "orcid": "0000-0001-9794-6852" }, { "family_name": "Ash", "given_name": "J.L.", "orcid": "0000-0003-4062-3942" }, { "family_name": "Bojanova", "given_name": "D.P.", "orcid": "0000-0001-7787-6682" }, { "family_name": "Buatier", "given_name": "M.D.", "orcid": "0000-0003-3863-5127" }, { "family_name": "Edgcomb", "given_name": "V.P.", "orcid": "0000-0001-6805-381X" }, { "family_name": "Galerne", "given_name": "C.Y.", "orcid": "0000-0001-9696-205X" }, { "family_name": "Gontharet", "given_name": "S.", "orcid": "0000-0002-8624-2654" }, { "family_name": "Heuer", "given_name": "V.B.", "orcid": "0000-0002-1856-116X" }, { "family_name": "Jiang", "given_name": "S.", "orcid": "0000-0001-6259-7912" }, { "family_name": "Kars", "given_name": "M.A.C.", "orcid": "0000-0002-4984-1412" }, { "family_name": "Khogenkumar Singh", "given_name": "S.", "orcid": "0000-0003-4536-3158" }, { "family_name": "Kim", "given_name": "J.", "orcid": "0000-0003-2430-3869" }, { "family_name": "Koornneef", "given_name": "L.M.T.", "orcid": "0000-0002-8016-1167" }, { "family_name": "Marsaglia", "given_name": "K.M.", "orcid": "0000-0001-5430-4630" }, { "family_name": "Meyer", "given_name": "N.R.", "orcid": "0000-0001-5436-1117" }, { "family_name": "Morono", "given_name": "Y.", "orcid": "0000-0001-8928-4254" }, { "family_name": "Negrete-Aranda", "given_name": "R.", "orcid": "0000-0003-3049-4374" }, { "family_name": "Neumann", "given_name": "F.", "orcid": "0000-0002-9666-5087" }, { "family_name": "Pastor", "given_name": "L.C.", "orcid": "0000-0001-9732-8907" }, { "family_name": "Pe\u00f1a-Salinas", "given_name": "M.E.", "orcid": "0000-0002-5835-0455" }, { "family_name": "P\u00e9rez Cruz", "given_name": "L.L." }, { "family_name": "Ran", "given_name": "L.", "orcid": "0000-0002-5198-2628" }, { "family_name": "Riboulleau", "given_name": "A.", "orcid": "0000-0002-2717-8330" }, { "family_name": "Sarao", "given_name": "J.A.", "orcid": "0000-0002-2014-1156" }, { "family_name": "Schubert", "given_name": "F.", "orcid": "0000-0002-1618-3978" }, { "family_name": "Stock", "given_name": "J.M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Toffin", "given_name": "L.M.A.A.", "orcid": "0000-0003-0012-1833" }, { "family_name": "Xie", "given_name": "W.", "orcid": "0000-0002-9742-9369" }, { "family_name": "Yamanaka", "given_name": "T.", "orcid": "0000-0002-6807-6904" }, { "family_name": "Zhuang", "given_name": "G.", "orcid": "0000-0002-6282-8415" } ], "abstract": "

International Ocean Discovery Program Expedition 385 drilled organic-rich sediments and intruded sills in the off-axis region and axial graben of the northern spreading segment of Guaymas Basin, a young marginal seafloor spreading system in the Gulf of California. Guaymas Basin is characterized by high heat flow and magmatism in the form of sill intrusions into sediments, which extends tens of kilometers off axis, in contrast with the localized volcanism found at most mid-ocean ridge spreading centers. Sill intrusions provide transient heat sources that mobilize buried sedimentary carbon, in part as methane and other hydrocarbons, and drive hydrothermal circulation. The resulting thermal and geochemical gradients shape abundance, composition, and activity of the deep subsurface biosphere of the basin.

\n

Drill sites extend over a broad region of Guaymas Basin. Adjacent Sites U1545 and U1546, located ~52 km northwest of the northern Guaymas Basin axial graben, recovered sediment successions to ~540 meters below seafloor (mbsf) (equivalent to the core depth below seafloor, Method A [CSF-A] scale), including a thin sill (a few meters thick) drilled near the bottom of Site U1545 and a massive sill (~355–430 mbsf) at Site U1546 that chemically and physically affects the surrounding sediments. Sites U1547 and U1548, located ~27 km northwest of the axial graben, were drilled to investigate an active sill-driven hydrothermal system evident at the seafloor as an 800 m wide, circular bathymetric high called Ringvent because of its outline of a ring of active vent sites. Ringvent is underlain by a thick sill at shallow depth (Site U1547). Geothermal gradients steepen toward the Ringvent periphery (Holes U1548A–U1548C), and the zones of authigenic carbonate precipitation and of highest microbial cell abundance correspondingly shallow toward the periphery. The underlying sill was drilled several times and yielded diverse igneous rock textures, sediment/sill interfaces, and alteration minerals in veins and vesicles. The Ringvent sill became the target of an integrated, interdisciplinary sampling and research effort that included geological, geochemical, and microbiological components. The thermal, lithologic, geochemical, and microbiological contrasts between the northwestern sites (U1545 and U1546) and the Ringvent sites (U1547 and U1548) form the core scientific observations informing the direct influence of sill-sediment interaction. These observations are supplemented by results from sites that exhibit persistent influence of thermally equilibrated sill intrusions, including supporting long-lived methane cold seeps, as observed at off-axis Sites U1549 and U1552, and the persistent geochemical record of hydrocarbon formation near the sill/sediment contact, as observed at the northern axial trough Site U1550, which confirms observations from Deep Sea Drilling Project (DSDP) Leg 64. Drilling at Site U1551 ~29 km southeast of the axial graben was not successful due to unstable shallow sands, but it confirmed the dominant influence of gravity-flow sedimentation processes southeast of the axial graben.

\n

The scientific outcomes of Expedition 385 will (1) revise long-held assumptions about the role of sill emplacement in subsurface carbon mobilization versus carbon retention, (2) comprehensively examine the subsurface biosphere of Guaymas Basin and its responses and adaptations to hydrothermal conditions, (3) redefine hydrothermal controls on authigenic mineral formation in sediments, and (4) yield new insights into the long term influence of sill-sediment interaction on sediments deposited at the earliest stages of seafloor spreading, that is, when spreading centers are proximal to a continental margin. The generally high quality and high degree of completeness of the shipboard data sets present opportunities for inter- and multidisciplinary collaborations during shore-based studies. In comparison to DSDP Leg 64 to Guaymas Basin in 1979, continuous availability of sophisticated drilling strategies (e.g., the advanced piston corer [APC] and half-length APC systems) and numerous analytical innovations greatly improved sample recovery and scientific yield, particularly in the areas of organic geochemistry and microbiology. For example, microbial metagenomics did not exist 40 y ago. However, these technical refinements do not change the fact that Expedition 385 in many respects builds on the foundations of understanding laid by Leg 64 drilling in Guaymas Basin.

", "doi": "10.14379/iodp.proc.385.101.2021", "issn": "2377-3189", "isbn": "978-1-954252-77-6", "publisher": "International Ocean Discovery Program", "publication": "Proceedings of the International Ocean Discovery Program", "publication_date": "2021-09-27", "volume": "385" }, { "id": "authors:3yp7q-ka160", "collection": "authors", "collection_id": "3yp7q-ka160", "cite_using_url": "https://authors.library.caltech.edu/records/3yp7q-ka160", "type": "book_section", "title": "Site U1550", "author": [ { "family_name": "Teske", "given_name": "A.", "orcid": "0000-0003-3669-5425" }, { "family_name": "Lizarralde", "given_name": "D.", "orcid": "0000-0001-6152-6039" }, { "family_name": "H\u00f6fig", "given_name": "T.W.", "orcid": "0000-0002-9254-4528" }, { "family_name": "Aiello", "given_name": "I.W.", "orcid": "0000-0001-9794-6852" }, { "family_name": "Ash", "given_name": "J.L.", "orcid": "0000-0003-4062-3942" }, { "family_name": "Bojanova", "given_name": "D.P.", "orcid": "0000-0001-7787-6682" }, { "family_name": "Buatier", "given_name": "M.D.", "orcid": "0000-0003-3863-5127" }, { "family_name": "Edgcomb", "given_name": "V.P.", "orcid": "0000-0001-6805-381X" }, { "family_name": "Galerne", "given_name": "C.Y.", "orcid": "0000-0001-9696-205X" }, { "family_name": "Gontharet", "given_name": "S.", "orcid": "0000-0002-8624-2654" }, { "family_name": "Heuer", "given_name": "V.B.", "orcid": "0000-0002-1856-116X" }, { "family_name": "Jiang", "given_name": "S.", "orcid": "0000-0001-6259-7912" }, { "family_name": "Kars", "given_name": "M.A.C.", "orcid": "0000-0002-4984-1412" }, { "family_name": "Khogenkumar Singh", "given_name": "S.", "orcid": "0000-0003-4536-3158" }, { "family_name": "Kim", "given_name": "J.", "orcid": "0000-0003-2430-3869" }, { "family_name": "Koornneef", "given_name": "L.M.T.", "orcid": "0000-0002-8016-1167" }, { "family_name": "Marsaglia", "given_name": "K.M.", "orcid": "0000-0001-5430-4630" }, { "family_name": "Meyer", "given_name": "N.R.", "orcid": "0000-0001-5436-1117" }, { "family_name": "Morono", "given_name": "Y.", "orcid": "0000-0001-8928-4254" }, { "family_name": "Negrete-Aranda", "given_name": "R.", "orcid": "0000-0003-3049-4374" }, { "family_name": "Neumann", "given_name": "F.", "orcid": "0000-0002-9666-5087" }, { "family_name": "Pastor", "given_name": "L.C.", "orcid": "0000-0001-9732-8907" }, { "family_name": "Pe\u00f1a-Salinas", "given_name": "M.E.", "orcid": "0000-0002-5835-0455" }, { "family_name": "P\u00e9rez Cruz", "given_name": "L.L." }, { "family_name": "Ran", "given_name": "L.", "orcid": "0000-0002-5198-2628" }, { "family_name": "Riboulleau", "given_name": "A.", "orcid": "0000-0002-2717-8330" }, { "family_name": "Sarao", "given_name": "J.A.", "orcid": "0000-0002-2014-1156" }, { "family_name": "Schubert", "given_name": "F.", "orcid": "0000-0002-1618-3978" }, { "family_name": "Stock", "given_name": "J.M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Toffin", "given_name": "L.M.A.A.", "orcid": "0000-0003-0012-1833" }, { "family_name": "Xie", "given_name": "W.", "orcid": "0000-0002-9742-9369" }, { "family_name": "Yamanaka", "given_name": "T.", "orcid": "0000-0002-6807-6904" }, { "family_name": "Zhuang", "given_name": "G.", "orcid": "0000-0002-6282-8415" } ], "abstract": "

Site U1550 is located within the axial graben of the northern Guaymas Basin spreading segment (Figures F1, F2). This site was established very close to Deep Sea Drilling Project (DSDP) Site 481 to take advantage of the known presence, depth, and characteristics of sills and indurated sediments at Site 481 (Shipboard Scientific Party, 1982), and to clarify its stratigraphy by redrilling it with improved coring tools and sampling approaches. Substantially improved recovery was expected relative to Site 481, leading to increased sampling resolution of downhole changes and enabling the use of modern microbiological approaches. The fault-bounded setting of Site U1550 provides the potential for high-flux fluid circulation in response to sill intrusion, leading to swift cooling and potentially enhanced alteration due to the rapid removal of dissolved phases and gases. The primary objectives for Site U1550 were to characterize the physical, chemical, and microbial responses to sill intrusion into sediments at a high-flux end-member location.

", "doi": "10.14379/iodp.proc.385.107.2021", "issn": "2377-3189", "isbn": "978-1-954252-77-6", "publisher": "International Ocean Discovery Program", "publication": "Proceedings of the International Ocean Discovery Program", "publication_date": "2021-09-27" }, { "id": "authors:rk3xg-t7n48", "collection": "authors", "collection_id": "rk3xg-t7n48", "cite_using_url": "https://authors.library.caltech.edu/records/rk3xg-t7n48", "type": "book_section", "title": "Site U1551", "author": [ { "family_name": "Teske", "given_name": "A.", "orcid": "0000-0003-3669-5425" }, { "family_name": "Lizarralde", "given_name": "D.", "orcid": "0000-0001-6152-6039" }, { "family_name": "H\u00f6fig", "given_name": "T.W.", "orcid": "0000-0002-9254-4528" }, { "family_name": "Aiello", "given_name": "I.W.", "orcid": "0000-0001-9794-6852" }, { "family_name": "Ash", "given_name": "J.L.", "orcid": "0000-0003-4062-3942" }, { "family_name": "Bojanova", "given_name": "D.P.", "orcid": "0000-0001-7787-6682" }, { "family_name": "Buatier", "given_name": "M.D.", "orcid": "0000-0003-3863-5127" }, { "family_name": "Edgcomb", "given_name": "V.P.", "orcid": "0000-0001-6805-381X" }, { "family_name": "Galerne", "given_name": "C.Y.", "orcid": "0000-0001-9696-205X" }, { "family_name": "Gontharet", "given_name": "S.", "orcid": "0000-0002-8624-2654" }, { "family_name": "Heuer", "given_name": "V.B.", "orcid": "0000-0002-1856-116X" }, { "family_name": "Jiang", "given_name": "S.", "orcid": "0000-0001-6259-7912" }, { "family_name": "Kars", "given_name": "M.A.C.", "orcid": "0000-0002-4984-1412" }, { "family_name": "Khogenkumar Singh", "given_name": "S.", "orcid": "0000-0003-4536-3158" }, { "family_name": "Kim", "given_name": "J.", "orcid": "0000-0003-2430-3869" }, { "family_name": "Koornneef", "given_name": "L.M.T.", "orcid": "0000-0002-8016-1167" }, { "family_name": "Marsaglia", "given_name": "K.M.", "orcid": "0000-0001-5430-4630" }, { "family_name": "Meyer", "given_name": "N.R.", "orcid": "0000-0001-5436-1117" }, { "family_name": "Morono", "given_name": "Y.", "orcid": "0000-0001-8928-4254" }, { "family_name": "Negrete-Aranda", "given_name": "R.", "orcid": "0000-0003-3049-4374" }, { "family_name": "Neumann", "given_name": "F.", "orcid": "0000-0002-9666-5087" }, { "family_name": "Pastor", "given_name": "L.C.", "orcid": "0000-0001-9732-8907" }, { "family_name": "Pe\u00f1a-Salinas", "given_name": "M.E.", "orcid": "0000-0002-5835-0455" }, { "family_name": "P\u00e9rez Cruz", "given_name": "L.L." }, { "family_name": "Ran", "given_name": "L.", "orcid": "0000-0002-5198-2628" }, { "family_name": "Riboulleau", "given_name": "A.", "orcid": "0000-0002-2717-8330" }, { "family_name": "Sarao", "given_name": "J.A.", "orcid": "0000-0002-2014-1156" }, { "family_name": "Schubert", "given_name": "F.", "orcid": "0000-0002-1618-3978" }, { "family_name": "Stock", "given_name": "J.M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Toffin", "given_name": "L.M.A.A.", "orcid": "0000-0003-0012-1833" }, { "family_name": "Xie", "given_name": "W.", "orcid": "0000-0002-9742-9369" }, { "family_name": "Yamanaka", "given_name": "T.", "orcid": "0000-0002-6807-6904" }, { "family_name": "Zhuang", "given_name": "G.", "orcid": "0000-0002-6282-8415" } ], "abstract": "

Site U1551 is located ~29 km southeast of the axial graben of the northern Guaymas Basin spreading segment (Figures F1, F2). The type of sediment, the depositional environment, and the type, size, and, presumably, age of sill intrusions were all predicted to differ in the southeastern side of the spreading segment relative to the northwestern side (Teske et al., 2018). The sediment at Site U1551 was predicted to be predominantly terrigenous and deposited as gravity-driven flows ranging from landslides to turbidites, with the underlying sills appearing to be larger and more saucer-shaped than those in the northwest. It was hypothesized that the physical and chemical properties of sediments may impact alteration in response to sill intrusion, and this may have consequences for carbon cycling. Moreover, the physical properties of the sediments may influence the size and shape of the sills beneath Site U1551. In turn, permeability might evolve toward enhanced induration, ultimately affecting the efficiency of alteration. Terrestrial organic carbon and metals are predicted to be more abundant in these sediments relative to the northwestern part of the basin, and this may also affect sediment alteration and its products. The primary scientific objective at Site U1551 was to constrain the influence of sediment type, an important factor controlling alteration and carbon cycling, on sill morphology by studying the response of predominantly terrigenous sediments to sill intrusion.

", "doi": "10.14379/iodp.proc.385.108.2021", "issn": "2377-3189", "isbn": "978-1-954252-77-6", "publisher": "International Ocean Discovery Program", "publication": "Proceedings of the International Ocean Discovery Program", "publication_date": "2021-09-27", "volume": "385" }, { "id": "authors:cng4e-mmw62", "collection": "authors", "collection_id": "cng4e-mmw62", "cite_using_url": "https://authors.library.caltech.edu/records/cng4e-mmw62", "type": "book_section", "title": "Site U1552", "author": [ { "family_name": "Teske", "given_name": "A.", "orcid": "0000-0003-3669-5425" }, { "family_name": "Lizarralde", "given_name": "D.", "orcid": "0000-0001-6152-6039" }, { "family_name": "H\u00f6fig", "given_name": "T.W.", "orcid": "0000-0002-9254-4528" }, { "family_name": "Aiello", "given_name": "I.W.", "orcid": "0000-0001-9794-6852" }, { "family_name": "Ash", "given_name": "J.L.", "orcid": "0000-0003-4062-3942" }, { "family_name": "Bojanova", "given_name": "D.P.", "orcid": "0000-0001-7787-6682" }, { "family_name": "Buatier", "given_name": "M.D.", "orcid": "0000-0003-3863-5127" }, { "family_name": "Edgcomb", "given_name": "V.P.", "orcid": "0000-0001-6805-381X" }, { "family_name": "Galerne", "given_name": "C.Y.", "orcid": "0000-0001-9696-205X" }, { "family_name": "Gontharet", "given_name": "S.", "orcid": "0000-0002-8624-2654" }, { "family_name": "Heuer", "given_name": "V.B.", "orcid": "0000-0002-1856-116X" }, { "family_name": "Jiang", "given_name": "S.", "orcid": "0000-0001-6259-7912" }, { "family_name": "Kars", "given_name": "M.A.C.", "orcid": "0000-0002-4984-1412" }, { "family_name": "Khogenkumar Singh", "given_name": "S.", "orcid": "0000-0003-4536-3158" }, { "family_name": "Kim", "given_name": "J.", "orcid": "0000-0003-2430-3869" }, { "family_name": "Koornneef", "given_name": "L.M.T.", "orcid": "0000-0002-8016-1167" }, { "family_name": "Marsaglia", "given_name": "K.M.", "orcid": "0000-0001-5430-4630" }, { "family_name": "Meyer", "given_name": "N.R.", "orcid": "0000-0001-5436-1117" }, { "family_name": "Morono", "given_name": "Y.", "orcid": "0000-0001-8928-4254" }, { "family_name": "Negrete-Aranda", "given_name": "R.", "orcid": "0000-0003-3049-4374" }, { "family_name": "Neumann", "given_name": "F.", "orcid": "0000-0002-9666-5087" }, { "family_name": "Pastor", "given_name": "L.C.", "orcid": "0000-0001-9732-8907" }, { "family_name": "Pe\u00f1a-Salinas", "given_name": "M.E.", "orcid": "0000-0002-5835-0455" }, { "family_name": "P\u00e9rez Cruz", "given_name": "L.L." }, { "family_name": "Ran", "given_name": "L.", "orcid": "0000-0002-5198-2628" }, { "family_name": "Riboulleau", "given_name": "A.", "orcid": "0000-0002-2717-8330" }, { "family_name": "Sarao", "given_name": "J.A.", "orcid": "0000-0002-2014-1156" }, { "family_name": "Schubert", "given_name": "F.", "orcid": "0000-0002-1618-3978" }, { "family_name": "Stock", "given_name": "J.M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Toffin", "given_name": "L.M.A.A.", "orcid": "0000-0003-0012-1833" }, { "family_name": "Xie", "given_name": "W.", "orcid": "0000-0002-9742-9369" }, { "family_name": "Yamanaka", "given_name": "T.", "orcid": "0000-0002-6807-6904" }, { "family_name": "Zhuang", "given_name": "G.", "orcid": "0000-0002-6282-8415" } ], "abstract": "

Site U1552 is located ~20 km northwest of the northern axial graben in Guaymas Basin (Figure F1), proximal to the Sonora margin (Figure F2). The site is adjacent to a mostly buried mound that sits atop a pipe-like, acoustically blanked zone that was observed in Seismic Line SO-112 (Figure F1) extending toward the edge of an interpreted sill intrusion at ~700 meters below seafloor (mbsf). Cold-seep seafloor communities are known to exist in the area above the edges of the interpreted deep sill. The mound structure is similar to the surficial mound near Site U1549, where gas hydrate is present at the seafloor, and it was thus expected that massive gas hydrate would be sampled in Hole U1552A, which is situated directly adjacent to the mostly buried mound. As at Site U1549, the association of a relatively deep sill, gas hydrates, and nearby seafloor communities connects multiple components of the carbon budget in a sediment deposition system influenced by a deep sill. Therefore, the primary objectives for Site U1552 were to characterize the physical, chemical, and microbial properties of this environment and to assess (1) the influence of the deep sill on interstitial water (IW) chemistry and gas hydrate stability, (2) the role of gas hydrate as a carbon storage buffer, (3) the utilization of permeable pathways between the sill and the seafloor for the transport of deep thermogenic gas, and (4) the impact of lateral gradients away from the pipe structure on microbial life.

", "doi": "10.14379/iodp.proc.385.109.2021", "issn": "2377-3189", "isbn": "978-1-954252-77-6", "publisher": "International Ocean Discovery Program", "publication": "Proceedings of the International Ocean Discovery Program", "publication_date": "2021-09-27", "volume": "385" }, { "id": "authors:r86d5-n7p07", "collection": "authors", "collection_id": "r86d5-n7p07", "cite_using_url": "https://authors.library.caltech.edu/records/r86d5-n7p07", "type": "book_section", "title": "Site U1549", "author": [ { "family_name": "Teske", "given_name": "A.", "orcid": "0000-0003-3669-5425" }, { "family_name": "Lizarralde", "given_name": "D.", "orcid": "0000-0001-6152-6039" }, { "family_name": "H\u00f6fig", "given_name": "T.W.", "orcid": "0000-0002-9254-4528" }, { "family_name": "Aiello", "given_name": "I.W.", "orcid": "0000-0001-9794-6852" }, { "family_name": "Ash", "given_name": "J.L.", "orcid": "0000-0003-4062-3942" }, { "family_name": "Bojanova", "given_name": "D.P.", "orcid": "0000-0001-7787-6682" }, { "family_name": "Buatier", "given_name": "M.D.", "orcid": "0000-0003-3863-5127" }, { "family_name": "Edgcomb", "given_name": "V.P.", "orcid": "0000-0001-6805-381X" }, { "family_name": "Galerne", "given_name": "C.Y.", "orcid": "0000-0001-9696-205X" }, { "family_name": "Gontharet", "given_name": "S.", "orcid": "0000-0002-8624-2654" }, { "family_name": "Heuer", "given_name": "V.B.", "orcid": "0000-0002-1856-116X" }, { "family_name": "Jiang", "given_name": "S.", "orcid": "0000-0001-6259-7912" }, { "family_name": "Kars", "given_name": "M.A.C.", "orcid": "0000-0002-4984-1412" }, { "family_name": "Khogenkumar Singh", "given_name": "S.", "orcid": "0000-0003-4536-3158" }, { "family_name": "Kim", "given_name": "J.", "orcid": "0000-0003-2430-3869" }, { "family_name": "Koornneef", "given_name": "L.M.T.", "orcid": "0000-0002-8016-1167" }, { "family_name": "Marsaglia", "given_name": "K.M.", "orcid": "0000-0001-5430-4630" }, { "family_name": "Meyer", "given_name": "N.R.", "orcid": "0000-0001-5436-1117" }, { "family_name": "Morono", "given_name": "Y.", "orcid": "0000-0001-8928-4254" }, { "family_name": "Negrete-Aranda", "given_name": "R.", "orcid": "0000-0003-3049-4374" }, { "family_name": "Neumann", "given_name": "F.", "orcid": "0000-0002-9666-5087" }, { "family_name": "Pastor", "given_name": "L.C.", "orcid": "0000-0001-9732-8907" }, { "family_name": "Pe\u00f1a-Salinas", "given_name": "M.E.", "orcid": "0000-0002-5835-0455" }, { "family_name": "P\u00e9rez Cruz", "given_name": "L.L." }, { "family_name": "Ran", "given_name": "L.", "orcid": "0000-0002-5198-2628" }, { "family_name": "Riboulleau", "given_name": "A.", "orcid": "0000-0002-2717-8330" }, { "family_name": "Sarao", "given_name": "J.A.", "orcid": "0000-0002-2014-1156" }, { "family_name": "Schubert", "given_name": "F.", "orcid": "0000-0002-1618-3978" }, { "family_name": "Stock", "given_name": "J.M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Toffin", "given_name": "L.M.A.A.", "orcid": "0000-0003-0012-1833" }, { "family_name": "Xie", "given_name": "W.", "orcid": "0000-0002-9742-9369" }, { "family_name": "Yamanaka", "given_name": "T.", "orcid": "0000-0002-6807-6904" }, { "family_name": "Zhuang", "given_name": "G.", "orcid": "0000-0002-6282-8415" } ], "abstract": "

Site U1549 is located ~9.5 km northwest of the northern axial graben of Guaymas Basin (Figure F1) and ~780 m northwest of a mound-shaped seafloor feature (Figure F2) where active cold-seep communities have been documented by preexpedition site surveys. In addition, seismic data at this location were interpreted to show an underlying sill at ~450 meters below seafloor (mbsf) and indicate gas movement along and around a pipe structure (Figure F2). This association of a relatively deep sill, active gas venting, and seafloor communities connects multiple components of the carbon budget of a sill-driven vent/seep system. The sedimentary setting at Site U1549 is intermediate between the biogenic-dominated sedimentation observed at Sites U1545 and U1546 and the dominantly terrigenous deposition documented southeast of the northern axial graben (Site U1551). The primary objectives for Site U1549 are thus to characterize the physical, chemical, and microbial properties of this sedimentologically intermediate setting and to assess the influence of the underlying sill and associated altered sediments on carbon cycling in the subseafloor.

", "doi": "10.14379/iodp.proc.385.106.2021", "issn": "2377-3189", "isbn": "978-1-954252-77-6", "publisher": "International Ocean Discovery Program", "publication": "Proceedings of the International Ocean Discovery Program", "publication_date": "2021-09-27", "volume": "385" }, { "id": "authors:6x7zc-hjb26", "collection": "authors", "collection_id": "6x7zc-hjb26", "cite_using_url": "https://authors.library.caltech.edu/records/6x7zc-hjb26", "type": "book_section", "title": "Site U1545", "author": [ { "family_name": "Teske", "given_name": "A.", "orcid": "0000-0003-3669-5425" }, { "family_name": "Lizarralde", "given_name": "D.", "orcid": "0000-0001-6152-6039" }, { "family_name": "H\u00f6fig", "given_name": "T.W.", "orcid": "0000-0002-9254-4528" }, { "family_name": "Aiello", "given_name": "I.W.", "orcid": "0000-0001-9794-6852" }, { "family_name": "Ash", "given_name": "J.L.", "orcid": "0000-0003-4062-3942" }, { "family_name": "Bojanova", "given_name": "D.P.", "orcid": "0000-0001-7787-6682" }, { "family_name": "Buatier", "given_name": "M.D.", "orcid": "0000-0003-3863-5127" }, { "family_name": "Edgcomb", "given_name": "V.P.", "orcid": "0000-0001-6805-381X" }, { "family_name": "Galerne", "given_name": "C.Y.", "orcid": "0000-0001-9696-205X" }, { "family_name": "Gontharet", "given_name": "S.", "orcid": "0000-0002-8624-2654" }, { "family_name": "Heuer", "given_name": "V.B.", "orcid": "0000-0002-1856-116X" }, { "family_name": "Jiang", "given_name": "S.", "orcid": "0000-0001-6259-7912" }, { "family_name": "Kars", "given_name": "M.A.C.", "orcid": "0000-0002-4984-1412" }, { "family_name": "Khogenkumar Singh", "given_name": "S.", "orcid": "0000-0003-4536-3158" }, { "family_name": "Kim", "given_name": "J.", "orcid": "0000-0003-2430-3869" }, { "family_name": "Koornneef", "given_name": "L.M.T.", "orcid": "0000-0002-8016-1167" }, { "family_name": "Marsaglia", "given_name": "K.M.", "orcid": "0000-0001-5430-4630" }, { "family_name": "Meyer", "given_name": "N.R.", "orcid": "0000-0001-5436-1117" }, { "family_name": "Morono", "given_name": "Y.", "orcid": "0000-0001-8928-4254" }, { "family_name": "Negrete-Aranda", "given_name": "R.", "orcid": "0000-0003-3049-4374" }, { "family_name": "Neumann", "given_name": "F.", "orcid": "0000-0002-9666-5087" }, { "family_name": "Pastor", "given_name": "L.C.", "orcid": "0000-0001-9732-8907" }, { "family_name": "Pe\u00f1a-Salinas", "given_name": "M.E.", "orcid": "0000-0002-5835-0455" }, { "family_name": "P\u00e9rez Cruz", "given_name": "L.L." }, { "family_name": "Ran", "given_name": "L.", "orcid": "0000-0002-5198-2628" }, { "family_name": "Riboulleau", "given_name": "A.", "orcid": "0000-0002-2717-8330" }, { "family_name": "Sarao", "given_name": "J.A.", "orcid": "0000-0002-2014-1156" }, { "family_name": "Schubert", "given_name": "F.", "orcid": "0000-0002-1618-3978" }, { "family_name": "Stock", "given_name": "J.M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Toffin", "given_name": "L.M.A.A.", "orcid": "0000-0003-0012-1833" }, { "family_name": "Xie", "given_name": "W.", "orcid": "0000-0002-9742-9369" }, { "family_name": "Yamanaka", "given_name": "T.", "orcid": "0000-0002-6807-6904" }, { "family_name": "Zhuang", "given_name": "G.", "orcid": "0000-0002-6282-8415" } ], "abstract": "

Site U1545 is located ~52 km northwest of the axial graben of the northern Guaymas Basin spreading segment (Figure F1). The primary objective for this site is shared with Site U1546, located just 1.1 km away (Figure F2). The expedition objective was to compare the sediments at two sites that are very close to each other but that have had, as seismic data suggest, very different degrees of alteration from intruding sills. Preexpedition seismic survey data indicate an undisturbed sedimentary succession at Site U1545 from the seafloor to ~2.8 s two-way traveltime (TWT) (~540 meters below seafloor [mbsf]), where an interpreted sill was observed. In contrast, seismic data show the same stratigraphic sequence at Site U1546 to be substantially disturbed between an apparent unconformity at ~2.3 s TWT and a bright reflector at ~2.6 s TWT (~350 mbsf), which was interpreted to be a sill intrusion. Sills deeper than 2.6 s TWT were also interpreted at Site U1546. Comparison of Sites U1545 and U1546 thus enables the quantification of thermal and hydrothermal alteration driven by sill intrusion at Site U1546.

", "doi": "10.14379/iodp.proc.385.103.2021", "issn": "2377-3189", "isbn": "978-1-954252-77-6", "publisher": "International Ocean Discovery Program", "publication": "Proceedings of the International Ocean Discovery Program", "publication_date": "2021-09-27", "volume": "385" }, { "id": "authors:8hbzt-62h25", "collection": "authors", "collection_id": "8hbzt-62h25", "cite_using_url": "https://authors.library.caltech.edu/records/8hbzt-62h25", "type": "book_section", "title": "Sites U1547 and U1548", "author": [ { "family_name": "Teske", "given_name": "A.", "orcid": "0000-0003-3669-5425" }, { "family_name": "Lizarralde", "given_name": "D.", "orcid": "0000-0001-6152-6039" }, { "family_name": "H\u00f6fig", "given_name": "T.W.", "orcid": "0000-0002-9254-4528" }, { "family_name": "Aiello", "given_name": "I.W.", "orcid": "0000-0001-9794-6852" }, { "family_name": "Ash", "given_name": "J.L.", "orcid": "0000-0003-4062-3942" }, { "family_name": "Bojanova", "given_name": "D.P.", "orcid": "0000-0001-7787-6682" }, { "family_name": "Buatier", "given_name": "M.D.", "orcid": "0000-0003-3863-5127" }, { "family_name": "Edgcomb", "given_name": "V.P.", "orcid": "0000-0001-6805-381X" }, { "family_name": "Galerne", "given_name": "C.Y.", "orcid": "0000-0001-9696-205X" }, { "family_name": "Gontharet", "given_name": "S.", "orcid": "0000-0002-8624-2654" }, { "family_name": "Heuer", "given_name": "V.B.", "orcid": "0000-0002-1856-116X" }, { "family_name": "Jiang", "given_name": "S.", "orcid": "0000-0001-6259-7912" }, { "family_name": "Kars", "given_name": "M.A.C.", "orcid": "0000-0002-4984-1412" }, { "family_name": "Khogenkumar Singh", "given_name": "S.", "orcid": "0000-0003-4536-3158" }, { "family_name": "Kim", "given_name": "J.", "orcid": "0000-0003-2430-3869" }, { "family_name": "Koornneef", "given_name": "L.M.T.", "orcid": "0000-0002-8016-1167" }, { "family_name": "Marsaglia", "given_name": "K.M.", "orcid": "0000-0001-5430-4630" }, { "family_name": "Meyer", "given_name": "N.R.", "orcid": "0000-0001-5436-1117" }, { "family_name": "Morono", "given_name": "Y.", "orcid": "0000-0001-8928-4254" }, { "family_name": "Negrete-Aranda", "given_name": "R.", "orcid": "0000-0003-3049-4374" }, { "family_name": "Neumann", "given_name": "F.", "orcid": "0000-0002-9666-5087" }, { "family_name": "Pastor", "given_name": "L.C.", "orcid": "0000-0001-9732-8907" }, { "family_name": "Pe\u00f1a-Salinas", "given_name": "M.E.", "orcid": "0000-0002-5835-0455" }, { "family_name": "P\u00e9rez Cruz", "given_name": "L.L." }, { "family_name": "Ran", "given_name": "L.", "orcid": "0000-0002-5198-2628" }, { "family_name": "Riboulleau", "given_name": "A.", "orcid": "0000-0002-2717-8330" }, { "family_name": "Sarao", "given_name": "J.A.", "orcid": "0000-0002-2014-1156" }, { "family_name": "Schubert", "given_name": "F.", "orcid": "0000-0002-1618-3978" }, { "family_name": "Stock", "given_name": "J.M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Toffin", "given_name": "L.M.A.A.", "orcid": "0000-0003-0012-1833" }, { "family_name": "Xie", "given_name": "W.", "orcid": "0000-0002-9742-9369" }, { "family_name": "Yamanaka", "given_name": "T.", "orcid": "0000-0002-6807-6904" }, { "family_name": "Zhuang", "given_name": "G.", "orcid": "0000-0002-6282-8415" } ], "abstract": "

Sites U1547 and U1548 are located ~27 km northwest of the axial graben of the northern Guaymas Basin (Figure F1). Site U1547 lies within a circular, bowl-shaped hydrothermal mound called Ringvent that rises ~20 m above the seafloor and has a maximum diameter of ~800 m. Three holes at Site U1548 (U1548A–U1548C) lie at the periphery of Ringvent’s southeastern edge, and two holes (U1548D and U1548E) are situated ~600 m west-northwest of Ringvent (Figure F2). Seismic profiles across Ringvent show a prominent subseafloor mound feature at ~0.06 s two-way traveltime (TWT) that is characterized by brightly reflective strata within the central bowl-shaped region. A bright reflector underlying the base of the bowl (at ~0.18 s TWT) is interpreted to be a sill intrusion. It is hypothesized that this and previous similar intrusions provided the heat that formed Ringvent and keep it active today. Ringvent is the best-characterized active, sill-associated hydrothermal system at an off-axis site in Guaymas Basin, and the temperature of its vent fluids varies between 20° and 75°C (Teske et al., 2019). Site survey data suggest that the central portion of Ringvent may thus function as a hydrothermal recharge zone. Therefore, Sites U1547 and U1548 were intended to core sediments and sills to explore patterns of hydrothermal circulation at Ringvent, which were suspected to be different within (Site U1547) and outside of (Holes U1548A–U1548C) the ring structure. The comparatively hot sill intrusion setting at Ringvent represents a shallow-emplacement end-member. The primary objectives for Sites U1547 and U1548 were to characterize the physical, chemical, and biological processes driven and affected by this end-member type of sill–sediment system, with a particular focus on the response of microbial communities to the expected steep temperature gradients at these sites. Moreover, two additional holes in an area near Ringvent were added to Site U1548 during the expedition (Holes U1548D and U1548E), with the joint objective of characterizing the geochemical signature of the abrupt lateral change in seismic character observed in sediment strata between ~2.39 and 2.42 s TWT, which may be related to a diagenetic change caused by the proximity to the igneous intrusions at Ringvent.

", "doi": "10.14379/iodp.proc.385.105.2021", "issn": "2377-3189", "isbn": "978-1-954252-77-6", "publisher": "International Ocean Discovery Program", "publication": "Proceedings of the International Ocean Discovery Program", "publication_date": "2021-09-27", "volume": "385" }, { "id": "authors:tb10k-zjp97", "collection": "authors", "collection_id": "tb10k-zjp97", "cite_using_url": "https://authors.library.caltech.edu/records/tb10k-zjp97", "type": "book_section", "title": "Site U1546", "author": [ { "family_name": "Teske", "given_name": "A.", "orcid": "0000-0003-3669-5425" }, { "family_name": "Lizarralde", "given_name": "D.", "orcid": "0000-0001-6152-6039" }, { "family_name": "H\u00f6fig", "given_name": "T.W.", "orcid": "0000-0002-9254-4528" }, { "family_name": "Aiello", "given_name": "I.W.", "orcid": "0000-0001-9794-6852" }, { "family_name": "Ash", "given_name": "J.L.", "orcid": "0000-0003-4062-3942" }, { "family_name": "Bojanova", "given_name": "D.P.", "orcid": "0000-0001-7787-6682" }, { "family_name": "Buatier", "given_name": "M.D.", "orcid": "0000-0003-3863-5127" }, { "family_name": "Edgcomb", "given_name": "V.P.", "orcid": "0000-0001-6805-381X" }, { "family_name": "Galerne", "given_name": "C.Y.", "orcid": "0000-0001-9696-205X" }, { "family_name": "Gontharet", "given_name": "S.", "orcid": "0000-0002-8624-2654" }, { "family_name": "Heuer", "given_name": "V.B.", "orcid": "0000-0002-1856-116X" }, { "family_name": "Jiang", "given_name": "S.", "orcid": "0000-0001-6259-7912" }, { "family_name": "Kars", "given_name": "M.A.C.", "orcid": "0000-0002-4984-1412" }, { "family_name": "Khogenkumar Singh", "given_name": "S.", "orcid": "0000-0003-4536-3158" }, { "family_name": "Kim", "given_name": "J.", "orcid": "0000-0003-2430-3869" }, { "family_name": "Koornneef", "given_name": "L.M.T.", "orcid": "0000-0002-8016-1167" }, { "family_name": "Marsaglia", "given_name": "K.M.", "orcid": "0000-0001-5430-4630" }, { "family_name": "Meyer", "given_name": "N.R.", "orcid": "0000-0001-5436-1117" }, { "family_name": "Morono", "given_name": "Y.", "orcid": "0000-0001-8928-4254" }, { "family_name": "Negrete-Aranda", "given_name": "R.", "orcid": "0000-0003-3049-4374" }, { "family_name": "Neumann", "given_name": "F.", "orcid": "0000-0002-9666-5087" }, { "family_name": "Pastor", "given_name": "L.C.", "orcid": "0000-0001-9732-8907" }, { "family_name": "Pe\u00f1a-Salinas", "given_name": "M.E.", "orcid": "0000-0002-5835-0455" }, { "family_name": "P\u00e9rez Cruz", "given_name": "L.L." }, { "family_name": "Ran", "given_name": "L.", "orcid": "0000-0002-5198-2628" }, { "family_name": "Riboulleau", "given_name": "A.", "orcid": "0000-0002-2717-8330" }, { "family_name": "Sarao", "given_name": "J.A.", "orcid": "0000-0002-2014-1156" }, { "family_name": "Schubert", "given_name": "F.", "orcid": "0000-0002-1618-3978" }, { "family_name": "Stock", "given_name": "J.M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Toffin", "given_name": "L.M.A.A.", "orcid": "0000-0003-0012-1833" }, { "family_name": "Xie", "given_name": "W.", "orcid": "0000-0002-9742-9369" }, { "family_name": "Yamanaka", "given_name": "T.", "orcid": "0000-0002-6807-6904" }, { "family_name": "Zhuang", "given_name": "G.", "orcid": "0000-0002-6282-8415" } ], "abstract": "

Site U1546 is located just 1.1 km away from Site U1545 and ~51 km northwest of the axial graben of the northern Guaymas Basin spreading segment (Figures F1, F2). The primary objective was to compare these two adjacent sites that have shared sedimentation history but very different degrees of alteration resulting from intruding sills. Preexpedition seismic survey data at Site U1546 revealed a bright reflector at ~2.6 s two-way traveltime (TWT) that was interpreted to be the contact with a sill intrusion. Disruption of the sedimentary strata above the interpreted sill (~2.3–2.6 s TWT) was supposed to have formed as a response to the sill emplacement. This feature abruptly terminates laterally toward Site U1545, coincident with the termination of the underlying sill. This same sedimentary sequence appears undisrupted at Site U1545 to ~2.8 s TWT, where another sill was observed in the seismic data. The shared objective for Sites U1545 and U1546 was to compare the composition, physical properties, geochemical gradients, and microbial communities at these sites. Thus, the major objective for Site U1546 was to provide a postintrusion sedimentary succession for comparison with reference Site U1545; this comparison will provide direct measurements of changes in response to sill intrusion.

", "doi": "10.14379/iodp.proc.385.104.2021", "issn": "2377-3189", "isbn": "978-1-954252-77-6", "publisher": "International Ocean Discovery Program", "publication": "Proceedings of the International Ocean Discovery Program", "publication_date": "2021-09-27", "volume": "385" }, { "id": "authors:wq0s5-e4j30", "collection": "authors", "collection_id": "wq0s5-e4j30", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171220-093808988", "type": "book_section", "title": "Source Functions and Path Effects from Earthquakes in the Farallon Transform Fault Region, Gulf of California, Mexico that Occurred on October 2013", "book_title": "Earthquakes and Multi-hazards Around the Pacific Rim", "author": [ { "family_name": "Castro", "given_name": "Ra\u00fal R.", "clpid": "Castro-R-R" }, { "family_name": "Stock", "given_name": "Joann M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Hauksson", "given_name": "Egill", "orcid": "0000-0002-6834-5051", "clpid": "Hauksson-E" }, { "family_name": "Clayton", "given_name": "Robert W.", "orcid": "0000-0003-3323-3508", "clpid": "Clayton-R-W" } ], "contributor": [ { "family_name": "Zhang", "given_name": "Yongxian", "clpid": "Zhang-Yongxian" }, { "family_name": "Goebel", "given_name": "Thomas", "clpid": "Goebel-T" }, { "family_name": "Peng", "given_name": "Zhigang", "clpid": "Peng-Zhigang" }, { "family_name": "Williams", "given_name": "Charles A.", "clpid": "Williams-C-A" }, { "family_name": "Yode", "given_name": "Mark", "clpid": "Yode-M" }, { "family_name": "Rundle", "given_name": "John B.", "clpid": "Rundle-J-B" } ], "abstract": "We determined source spectral functions, Q and site effects using regional records of body waves from the October 19, 2013 (M_w = 6.6) earthquake and eight aftershocks located 90 km east of Loreto, Baja California Sur, Mexico. We also analyzed records from a foreshock with magnitude 3.3 that occurred 47 days before the mainshock. The epicenters of this sequence are located in the south-central region of the Gulf of California (GoC) near and on the Farallon transform fault. This is one of the most active regions of the GoC, where most of the large earthquakes have strike\u2013slip mechanisms. Based on the distribution of the aftershocks, the rupture propagated northwest with a rupture length of approximately 27 km. We calculated 3-component P- and S-wave spectra from ten events recorded by eleven stations of the Broadband Seismological Network of the GoC (RESBAN). These stations are located around the GoC and provide good azimuthal coverage (the average station gap is 39\u25e6). The spectral records were corrected for site effects, which were estimated calculating average spectral ratios between horizontal and vertical components (HVSR method). The site-corrected spectra were then inverted to determine the source functions and to estimate the attenuation quality factor Q. The values of Q resulting from the spectral inversion can be approximated by the relations Q_P = 48.1 1\u00b11^(f0:880:04) and QS = 135:4 1:1f \u00b1^(0:580:03) and are consistent with previous estimates reported by Vidales-Basurto et al. (Bull Seism Soc Am 104:2027\u20132042, 2014) for the south-central GoC. The stress drop estimates, obtained using the \u03c9^2 model, are below 1.7 MPa, with the highest stress drops determined for the mainshock and the aftershocks located in the ridge zone. We used the values of Q obtained to recalculate source and site effects with a different spectral inversion scheme. We found that sites with low S-wave amplification also tend to have low P-wave amplification, except for stations BAHB, GUYB and SFQB, located on igneous rocks, where the P-wave site amplification is higher.", "doi": "10.1007/978-3-319-71565-0_4", "isbn": "978-3-319-71564-3", "publisher": "Birkh\u00e4user", "place_of_publication": "Cham, Switzerland", "publication_date": "2017-12-21", "pages": "45-62" }, { "id": "authors:0cdkz-9gr67", "collection": "authors", "collection_id": "0cdkz-9gr67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140425-103722434", "type": "book_section", "title": "Seismic Calibration Shots Conducted in 2009 in the Imperial Valley, Southern California, for the Salton Seismic Imaging Project (SSIP)", "author": [ { "family_name": "Murphy", "given_name": "Janice", "clpid": "Murphy-J-M" }, { "family_name": "Goldman", "given_name": "Mark", "clpid": "Goldman-M" }, { "family_name": "Fuis", "given_name": "Gary", "clpid": "Fuis-G-S" }, { "family_name": "Rymer", "given_name": "Michael", "clpid": "Rymer-M-J" }, { "family_name": "Sickler", "given_name": "Robert", "clpid": "Sickler-R" }, { "family_name": "Miller", "given_name": "Summer", "clpid": "Miller-S" }, { "family_name": "Butcher", "given_name": "Lesley", "clpid": "Butcher-L" }, { "family_name": "Ricketts", "given_name": "Jason", "clpid": "Ricketts-J" }, { "family_name": "Criley", "given_name": "Coyn", "clpid": "Criley-C" }, { "family_name": "Stock", "given_name": "Joann", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Hole", "given_name": "John", "clpid": "Hole-J" }, { "family_name": "Chavez", "given_name": "Greg", "clpid": "Chavez-G" } ], "abstract": "The Salton Seismic Imaging Project (SSIP) is a large-scale collaborative project with the goal of developing a detailed 3-D structural image of the Salton Trough (including both the Coachella and Imperial Valleys). The image will be used for earthquake hazard analysis, geothermal studies, and studies of plate-boundary transition from an ocean-ocean to a continent-continent plate-boundary.\nAs part of SSIP, a series of calibration shots were detonated in June 2009 in the southern Imperial Valley for four specific reasons: (1) to measure peak particle velocity and acceleration at various distances from the shots, (2) to calibrate the propagation of energy through sediments of the Imperial Valley, (3) to test the effects of seismic energy on buried clay drainage pipes, which are abundant throughout the irrigated parts of the Salton Trough, and (4) to test the ODEX drilling technique, which uses a downhole casing hammer for a tight casing fit.\nCurrently, we are using information obtained from the calibration shots to plan the data collection phase of the SSIP project. We have validated the use of ground-motion tables developed with Los Angeles Region Seismic Experiment (LARSE) data for use in the Imperial Valley and we have demonstrated that seismic energy from shots will not damage the drainage pipes used throughout the Salton Trough for irrigation.", "publisher": "U. S. Geological Survey", "publication_date": "2011" }, { "id": "authors:g1725-vx726", "collection": "authors", "collection_id": "g1725-vx726", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141017-125224927", "type": "book_section", "title": "Constraints on the timing of extension in the Northern Basin, Ross Sea", "book_title": "Antarctica: Contributions to Global Earth Sciences", "author": [ { "family_name": "Cande", "given_name": "Steven C.", "clpid": "Cande-S-C" }, { "family_name": "Stock", "given_name": "Joann M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" } ], "contributor": [ { "family_name": "F\u00fctterer", "given_name": "Dieter Karl", "clpid": "F\u00fctterer-D-K" }, { "family_name": "Damaske", "given_name": "Detlef", "clpid": "Damaske-D" }, { "family_name": "Kleinschmidt", "given_name": "Georg", "clpid": "Kleinschmidt-G" }, { "family_name": "Miller", "given_name": "Hubert", "clpid": "Miller-H" }, { "family_name": "Tessensohn", "given_name": "Franz", "clpid": "Tessensohn-F" } ], "abstract": "Recent kinematic constraints for the region north of the western Ross Sea suggest that there was approximately 150 km of seafloor spreading in the Adare Basin, northeast of Cape Adare, between Chrons 20 and 8 (43 to 26 Ma). This kinematic history has important implications since the 150 km of extension in the Adare Basin occurred immediately north along strike from the Northern Basin of the Ross Sea, whose extensional history is not well known. This paper examines the transition from the structures in the Adare Basin to the structures of the Northern Basin and speculates on the manner in which the extension was accommodated in the Ross Sea. Magnetic anomaly data in the Adare Basin document a sequence of anomalies 18 to 12 formed during a period of very slow spreading. The easternmost part of this sequence, anomalies 16 to 18, coalesces into a single positive anomaly near 72\u00b0 S, forming a distinct anomaly that can be traced southward from the Adare Basin across the continental margin and down the east side of the Northern Basin to a latitude of roughly 73\u00b0 S. This observation has important implications for the tectonic history of the Ross Sea since it suggests that most of the extension in the Adare Basin continued into the Northern Basin. This, in turn, suggests that the Northern Basin was formed by a combination of crustal thinning and massive, narrowly focused intrusions.", "isbn": "978-3-540-30673-3", "publisher": "Springer-Verlag Berlin Heidelberg", "place_of_publication": "Berlin", "publication_date": "2006", "pages": "319-326" }, { "id": "authors:05dv0-z5h44", "collection": "authors", "collection_id": "05dv0-z5h44", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140425-125510082", "type": "book_section", "title": "Cenozoic Reconstructions of the Australia-New Zealand-South Pacific Sector of Antarctica", "book_title": "The Cenozoic Southern Ocean: tectonics, sedimentation, and climate change between Australia and Antarctica", "author": [ { "family_name": "Cande", "given_name": "Steven C.", "clpid": "Cande-S-C" }, { "family_name": "Stock", "given_name": "Joann M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" } ], "contributor": [ { "family_name": "Exon", "given_name": "N. F.", "clpid": "Exon-N-F" }, { "family_name": "Kennett", "given_name": "James P.", "clpid": "Kennett-J-P" }, { "family_name": "Malone", "given_name": "Mitchell J.", "clpid": "Malone-M-J" } ], "abstract": "Reconstructions are presented documenting the relative motion of the Australia.\nAntarctic and Pacific plates since Chron 27 (61.1 Ma). In addition to the motion of\nthe major plates, the reconstructions show the relative motion between East and\nWest Antarctica and the continental fragments that make up the South Tasman\nRise. Recent observations that are used in making these reconstructions include the\nmapping of seafloor spreading magnetic anomalies in the Adare basin, northeast of\nCape Adare, which recorded roughly 150 km of opening between East and West\nAntarctica between Chrons 20 (43.8 Ma) and 8 (26.6 Ma). In addition, magnetic\nand bathymetric observations from the lselin Rift, northeast of the Iselin Bank, and\nfrom the Emerald Fracture Zone, along the western boundary of Pacific-Antarctic\nspreading, document the rotation of the Iselin Bank between Chrons 27 and 24\n(53.3 Ma). Our reconstructions indicate that there was a total of about 200 km of\nseparation between East and West Antarctica in the northern Ross Sea region in the\nCenozoic. These reconstructions document the development of a deep-water\npassageway between Australia and Antarctica as the South Tasman Rise clears the\nfinal piece of the Antarctic continental margin around Chron 13 (33.5 Ma).", "doi": "10.1029/151GM02", "isbn": "9780875904160", "publisher": "American Geophysical Union", "place_of_publication": "Washington, DC", "publication_date": "2004", "pages": "5-17" }, { "id": "authors:5x7mx-51c26", "collection": "authors", "collection_id": "5x7mx-51c26", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140422-142537032", "type": "book_section", "title": "Cenozoic volcanism and tectonics of the continental margins of the Upper Delf\u00edn basin, northeastern Baja California and western Sonora", "book_title": "Tectonic evolution of northwestern M\u00e9xico and the southwestern USA", "author": [ { "family_name": "Oskin", "given_name": "Michael", "orcid": "0000-0002-6631-5326", "clpid": "Oskin-M-E" }, { "family_name": "Stock", "given_name": "Joann", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" } ], "contributor": [ { "family_name": "Johnson", "given_name": "S. E.", "clpid": "Johnson-S-E" }, { "family_name": "Paterson", "given_name": "S. R.", "clpid": "Paterson-S-R" }, { "family_name": "Fletcher", "given_name": "J. M.", "clpid": "Fletcher-J-M" }, { "family_name": "Girty", "given_name": "G. H.", "clpid": "Girty-G-H" }, { "family_name": "Kimbrough", "given_name": "D. L.", "clpid": "Kimbrough-D-L" }, { "family_name": "Mart\u00edn-Barajas", "given_name": "A.", "clpid": "Mart\u00edn-Barajas-A" } ], "abstract": "Pre- and syn-rift stratigraphy of conjugate rifted margins of the Upper Delf\u00edn\nbasin provides a rare opportunity to explore proximal relationships between the loci\nof volcanism and rifting during formation of new ocean basin. The Upper Delf\u00edn basin\nis one of a series of youthful, en-echelon ocean basins that accommodate spreading\nbetween the Pacific and North American plates in the Gulf of California. Four groups\nof volcaniclastic stratigraphy are described from the Baja California rifted margin\nfrom the Pucrtecitos Volcanic Province to the Sierra San Felipe and from the conjugate\nSonora rifted margin from Isla Tibur\u00f3n to the adjacent mainland coastal\nregion. Excluding the uppermost post-6 Ma group, these strata predate opening of\nthe Upper Delf\u00edn basin and thus similar facies relationships occur on both conjugate\nrift margins. Pre-rift, mostly arc-related volcanism from 21 to 12 Ma built isolated\nvolcanic centers over a regional Eocene(?) erosion surface cut onto pre-Tertiary\nbasement rocks. The Puertecitos Volcanic Province formed as a concentration of arcrelated\nvolcanism with a peak of activity at 18-15 Ma. Rift-related faulting and basin\nformation initiated after 12.6 Ma to the north and cast of the Puertecitos Volcanic\nProvince, but extension largely bypassed the center of the volcanic province. Rather,\nrifting stepped eastward along the Matomi Accommodation Zone, perhaps by taking\nadvantage of crust weakened by prior arc-related volcanism in the Puertecitos Volcanic\nProvince. Later rift-related volca nism localized along intersections of the Mato mi\nAccommodation Zone and north-striking extensional faults. The crustal break that\nopened the Upper Delf\u00edn basin ca. 6 Ma coincides with the most voluminous exposures\nof late Miocene syn-rift volcanism and the vent area for 6.7-6.1 Ma rhyolite\nignimbrites that blanketed the region just prior to the onset of marine sedimentation.\nOverall, the pattern of arc- and rift-related volcanism, sedimentation, and faulting on\nthe margins of the Upper Delf\u00edn basin indicates a close association between continental\nextension and volcanism. These relationships support that magmatism and crustal\nrift structure evolved as a coupled system to localize Pacific-North America plate\nmotion into the Gulf of California.", "doi": "10.1130/0-8137-2374-4.421", "isbn": "9780813723747", "publisher": "Geological Society of America", "place_of_publication": "Boulder, CO", "publication_date": "2003", "pages": "421-438" }, { "id": "authors:z2k1g-avz03", "collection": "authors", "collection_id": "z2k1g-avz03", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140423-104037295", "type": "book_section", "title": "Tectonic history of Antarctic seafloor in the Australia-New Zealand-South Pacific sector: implications for Antarctic continental tectonics", "book_title": "Antarctica at the close of a Millennium", "author": [ { "family_name": "Stock", "given_name": "J. M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Cande", "given_name": "S. C.", "clpid": "Cande-S-C" } ], "contributor": [ { "family_name": "Gamble", "given_name": "John A.", "clpid": "Gamble-J-A" }, { "family_name": "Skinner", "given_name": "David N. B.", "clpid": "Skinner-D-N-B" }, { "family_name": "Henrys", "given_name": "Stuart A.", "clpid": "Henrys-S-A" } ], "abstract": "We review the seafloor spreading record of plate motions adjacent to the Antarctic continent during and after Cretaceous separation of the New Zealand and Australia continental fragments from Antarctica. The earliest seafloor in this region (c. 95-83 Ma) records separation of Australia from Antarctica and separation of the Lord Howe rise from eastern Australia. At this time, continental extension occurred between the Campbell Plateau/Chatham Rise and Marie Byrd Land with oblique subduction of Phoenix plate fragments (Aluk and Bellingshausen) beneath the West Antarctic margin from c. 125\u00baW to at least 90\u00baW. Seafloor spreading started first (Chron 34, before 83 Ma) in the mouth of the rift, between the Chatham Rise and the Bellingshausen plate, and later (Chron 33, c. 79 Ma) between the Campbell Plateau and Marie Byrd Land, joining the Tasman sea ridge to the southwest Pacific spreading centre. Subsequent tectonic events include: (1) <50 km of rifting of the seafloor adjacent to Marie Byrd Land along the northeast-trending Iselin trough, east of the Iselin Bank, from Chrons 27 to 24 (61-55 Ma); (2) propagation of the southeast Indian Ridge between the south Tasman Rise and Victoria Land to join the Tasman Sea spreading centre by Chron 27 (61 Ma); (3) capture of the Bellingshausen plate by West Antarctica by about Chron 27; (4) 150-180 km of separation between East Antarctica and West Antarctica (Iselin Bank) centred on the NNW-trending Adare trough between Chrons 18 and 9 (40-27 Ma). These observations predict, first, that the West Antarctic margin at 125\u00baW was the site of a triple junction from at least 84 to 61 Ma, with Phoenix plate annihilation and expected tectonics of West Antarctica in many ways analogous to breakup of the Farallon plate and its effects on western North America. Second, northern Victoria Land may exhibit unique tectonics compared to elsewhere along this part of the Antarctic margin because it lay in a continental strike-slip regime, sliding against continental crust of the Australia plate (western south Tasman Rise) until Eocene time. Finally, the 150+ km of Oligocene seafloor formed at the Adare Trough implies a significant extensional event of this age farther south in the Ross Sea, in agreement with results from recent drilling at Cape Roberts hole CRP-3.", "isbn": "1877264067", "publisher": "Royal Society of New Zealand; Wellington", "place_of_publication": "Wellington, NZ", "publication_date": "2002", "pages": "251-259" }, { "id": "authors:225k9-yev63", "collection": "authors", "collection_id": "225k9-yev63", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140416-154731979", "type": "book_section", "title": "Mesozoic/Cenozoic Tectonic Events Around Australia", "book_title": "History and Dynamics of Global Plate Motions", "author": [ { "family_name": "M\u00fcller", "given_name": "R. Dietmar", "orcid": "0000-0002-3334-5764", "clpid": "M\u00fcller-R-D" }, { "family_name": "Gain\u0103", "given_name": "Carmen", "clpid": "Gain\u0103-C" }, { "family_name": "Tikku", "given_name": "Anahita", "clpid": "Tikku-A" }, { "family_name": "Mihut", "given_name": "Dona", "clpid": "Mihut-D" }, { "family_name": "Cande", "given_name": "Steven C.", "clpid": "Cande-S-C" }, { "family_name": "Stock", "given_name": "Joann M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" } ], "contributor": [ { "family_name": "Richards", "given_name": "Mark A.", "clpid": "Richards-M-A" }, { "family_name": "Gordon", "given_name": "Richard G.", "clpid": "Gordon-R-G" }, { "family_name": "Van der Hilst", "given_name": "Robert Dirk", "clpid": "Van-der-Hilst-R-D" } ], "abstract": "We use an absolute and relative plate motion model for the plates around\nAustralia to identify major plate tectonic events, evaluate their causes, and investigate\ntheir effects on anomalous intraplate subsidence or uplift and on the history\nof oceanic crustal accretion. An event at ~136 Ma is marked by the onset of sea\nfloor spreading between Greater India and Australia. At about this time long-lived\nsubduction east of Australia ceased, probably due to subduction of the\nPhoenix-Pacific spreading ridge, changing this plate boundary to a transform\nmargin. Between 130 and 80 Ma, Australia and East Antarctica moved eastward\nin the Atlantic-Indian mantle hotspot reference frame. This can be plausibly\nlinked to ridge push from the NW -SE oriented spreading center NW of Australia\nand to the inferred geometry and continued subduction of the Phoenix plate\nbeneath the West Antarctic margin. A drastic change in spreading direction\nbetween the Indian and Australian plates from NE-SW to N-S occurred at about\n99 Ma, possibly caused by a change in absolute motion of the Pacific Plate.\nChron 27 (~61 Ma) marks the onset of relative motion between East and West\nAntarctica, and a change in the relative motion between Australia and Antarctica.\nIt may be linked to the subduction of a segment of the Neo-Tethyan Ridge. Both\nevents caused anomalous subsidence on the Northwest Shelf of Australia. The\nalmost stationary position of Australia w.r.t. the mantle from -80 Ma to -40 Ma\nmay reflect the progressive subduction of the Pacific-Phoenix ridge to the east of\nNew Zealand preceding 80 Ma, resulting in a diminished trench suction force east\nof Australia. Preliminary reconstructions to close the Pacific-Australian plate\ncircuit based on recently collected geophysical data indicate that a tectonic event\nat 43 Ma may mark the onset of renewed subduction east of Australia. At the\nsame time spreading in the Wharton Basin between India and Australia ceased,\nand tectonic reactivation is recorded in the Bass Strait. Excess late Tertiary subsidence\non the northwest shelf of >500 m matches the anomalous depth of the Argo abyssal plain ocean floor. This anomalous subsidence may express largescale\nintraplate deformation in the Indian Ocean. Asymmetries in oceanic crustal\naccretion around Australia are caused mainly by hotspot-ridge and coldspot-ridge\ninteraction.", "doi": "10.1029/GM121p0161", "isbn": "9780875909790", "publisher": "American Geophysical Union", "place_of_publication": "Washington, DC", "publication_date": "2000", "pages": "161-188" }, { "id": "authors:c9gnk-mvk84", "collection": "authors", "collection_id": "c9gnk-mvk84", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140416-153704888", "type": "book_section", "title": "Fast Paleogene Motion of the Pacific Hotspots From Revised Global Plate Circuit Constraints", "book_title": "History and Dynamics of Global Plate Motions", "author": [ { "family_name": "Raymond", "given_name": "Carol A.", "orcid": "0000-0002-4213-8097", "clpid": "Raymond-Carol-A" }, { "family_name": "Stock", "given_name": "Joann M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Cande", "given_name": "Steven C.", "clpid": "Cande-S-C" } ], "contributor": [ { "family_name": "Richards", "given_name": "Mark A.", "clpid": "Richards-M-A" }, { "family_name": "Gordon", "given_name": "Richard G.", "clpid": "Gordon-R-G" }, { "family_name": "Van der Hilst", "given_name": "Robert Dirk", "clpid": "Van-der-Hilst-R-D" } ], "abstract": "Major improvements in Late Cretaceous-early Tertiary Pacific-Antarctica\nplate reconstructions, and new East-West Antarctica rotations, allow a more\ndefinitive test of the relative motion between hotspots using global plate circuit\nreconstructions with quantitative uncertainties. The hotspot reconstructions,\nusing an updated Pacific-hotspot kinematic model, display significant misfits of\nobserved and reconstructed hotspot tracks in the Pacific and Indian Oceans.\nThe misfits imply motions of 5-80 mm/yr throughout the Cenozoic between the\nAfrican-Indian hotspot group and the Hawaiian hotspot. Previously recognized\nmisfits between reconstructed Pacific plate paleomagnetic poles and those of\nother plates might be accounted for within the age uncertainty of the\npaleomagnetic poles, and non-dipole field contributions. We conclude that the\nderived motion of the Hawaiian hotspot relative to the Indo-Atlantic hotspots\nbetween 61 Ma and present is a robust result. Thus, the Pacific hotspot\nreference frame cannot be considered as fixed relative to the deep mantle. The\nbend in the Hawaiian-Emperor Seamount chain at 43 Ma resulted from a\nspeedup in the absolute motion of the Pacific plate in a westward direction\nduring a period of southward migration of the hotspot. The relationship between\nthe hotspot motion and plate motion at Hawaii suggests two possible scenarios:\nan entrainment of the volcanic sources in the asthenosphere beneath the rapidly\nmoving plate while the hotspot source drifted in a plate-driven counterflow\ndeeper within the mantle, or drift of the hotspot source which was independent\nof the plate motion, but responded to common forces, producing synchronous\nchanges in hotspot and plate motion during the early Tertiary.", "doi": "10.1029/GM121p0359", "isbn": "9780875909790", "publisher": "American Geophysical Union", "place_of_publication": "Washington, DC", "publication_date": "2000", "pages": "359-375" }, { "id": "authors:0hz6s-s9361", "collection": "authors", "collection_id": "0hz6s-s9361", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140422-074216122", "type": "book_section", "title": "Relation of the Puertecitos Volcanic Province, Baja California, Mexico, to development of the plate boundary in the Gulf of California", "book_title": "Cenozoic Tectonics and Volcanism of Mexico", "author": [ { "family_name": "Stock", "given_name": "Joann M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" } ], "contributor": [ { "family_name": "Delgado-Granados", "given_name": "Hugo", "clpid": "Delgado-Granados-H" }, { "family_name": "Aguirre-D\u00edaz", "given_name": "Gerardo J.", "clpid": "Aguirre-D\u00edaz-G-J" }, { "family_name": "Stock", "given_name": "J. M.", "clpid": "Stock-J-M" } ], "abstract": "The Puertecitos Volcanic Province is a late Miocene and Pliocene ignimbrite field\ncovering an area of ~2600 km^2, with an estimated erupted volume of at least 500 km^3. It\nis unique on the Baja California Peninsula in terms of both its volume and age. It lies at\na 35\u00b0 bend in the edge of the Gulf of California rift system, at a location where the character\nof the Gulf extensional province, in terms of topography, style of faulting, and\npaleomagnetic rotations, changes dramatically along strike.\nThis chapter presents a speculative model linking the along-strike structural variations\nof the extensional province at this location, and the two major episodes of volcanism\nin the Puertecitos Volcanic Province ca. 6 Ma and 3 Ma, to events in the\nevolution of the spreading and transform system nearby in the Gulf of California. Two\nfracture zone systems project northwestward into the Puertecitos Volcanic Province.\nThe Guaymas transform fault system passes through the Ballenas Channel and is\naligned with the southern boundary of the volcanic province; the Tibur\u00f3n fracture\nzone (between Isla Tibur\u00f3n and Isla Angel de la Guarda) projects into the northcentral\npart of the province. The Tibur\u00f3n fracture zone was important during the\nearly evolution of the Gulf of California. The Guaymas transform fault system was\nmuch shorter during the early evolution of the Gulf of California was only active near\nthe Puertecitos Volcanic Province after 2 Ma. The Tibur\u00f3n fracture zone may have\nbeen connected to a west-northwest-trending zone of deformation on land, the\nMatomi accommodation zone. Regional field evidence suggests that this accommoda:\ntion zone was active in late Miocene time and may have localized most of the vents for\nthe voluminous ca. 6 Ma volcanism of the northern Puerteci tos Volcanic Province. An\nepisode of 3.3-2.7 Ma volcanism in the extending region is related to a Pliocene jump\nof one Gulf of California spreading center from the Tibur\u00f3n basin into this area\n(which is now the lower Delfin basin). Continental extension, growth faulting, and\nbasin formation in Pliocene time in the southern part of the Puertecitos Volcanic\nProvince probably preceded this spreading center jump by 1 to 2 m.y.\nThe temporal and spatial aspects of extension in this model may explain the\nstructural transition seen in the Puertecitos region. North of the Puertecitos Volcanic\nProvince, the San Pedro Martir fault and basin and range topography partly reflect\npre-6 Ma extension. Regions to the south, from Puertecitos southward to Gonzaga\nBay, may have been unaffected by extension at this time. The pre-Pliocene rift margin\nprobably passed through the northeast part of the province and southeastward into\nthe Gulf of California, east of Isla Angel de la Guarda. When major deformation began to affect the main part of the volcanic province, the motion in the sector from\nPuertecitos to Gonzaga Bay may have been primarily transform in nature, producing\na very different structural style from that inherited from the earlier transtensional\nhistory in the region north of the Matomi accommodation zone.", "doi": "10.1130/0-8137-2334-5.143", "isbn": "9780813723341", "publisher": "Geological Society of America", "place_of_publication": "Boulder, CO", "publication_date": "2000", "pages": "143-156" }, { "id": "authors:p0vmv-mc408", "collection": "authors", "collection_id": "p0vmv-mc408", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140415-074340042", "type": "book_section", "title": "Pacific North America plate tectonics of the Neogene southwestern United States: An update", "book_title": "Integrated earth and environmental evolution of the southwestern United States: the Clarence A. Hall, Jr. volume", "author": [ { "family_name": "Atwater", "given_name": "Tanya", "clpid": "Atwater-T" }, { "family_name": "Stock", "given_name": "Joann", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" } ], "contributor": [ { "family_name": "Hall", "given_name": "Clarence A.", "clpid": "Hall-C-A" }, { "family_name": "Ernst", "given_name": "W. G.", "clpid": "Ernst-W-G" }, { "family_name": "Nelson", "given_name": "Clemens Arvid", "clpid": "Nelson-C-A" } ], "abstract": "We use updated rotations within the Pacific-Antarctica-Africa-North America plate circuit\nto calculate Pacific-North America plate reconstructions for times since chron 13 (33 Ma). The\ndirection of motion of the Pacific plate relative to stable North America was fairly steady between\nchrons 13 and 4, and then changed and moved in a more northerly direction from chron 4 to the\npresent (8 Ma to the present). No Pliocene changes in Pacific-North America plate motion are\nresolvable in these data, suggesting that Pliocene changes in deformation style along the\nboundary were not driven by changes in plate motion. However, the chron 4 change in\nPacific-North America plate motion appears to correlate very closely to a change in direction of\nextension documented between the Sierra Nevada and the Colorado Plateau. Our best solution\nfor the displacement with respect to stable North America of a point on the Pacific plate that is\nnow near the Mendocino triple junction is that from 30 to 12 Ma the point was displaced along an\nazimuth of ~N60\u00b0W at rate of ~33 mm/yr; from 12 Ma to about 8 Ma the azimuth of\ndisplacement was about the same as previously, but the rate was faster (~52 mm/yr); and since 8\nMa the point was displaced along an azimuth of N37\u00b0W at a rate of ~52 mm/yr.\nWe compare plate-circuit reconstructions of the edge of the Pacific plate to continental\ndeformation reconstructions of North American tectonic elements across the Basin and Range\nprovince and elsewhere in order to evaluate the relationship of this deformation to the plate\nmotions. The oceanic displacements correspond remarkably well to the continental reconstructions where deformations of the latter have been quantified along a path across the Colorado\nPlateau and central California. They also supply strong constraints for the deformation budgets\nof regions to the north and south, in Cascadia and northern Mexico, respectively.\nWe examine slab-window formation and evolution in a detailed re-analysis of the spreading\ngeometry of the post-Farallon microplates, from 28 to 19 Ma: Development of the slab window\nseems linked to early Miocene volcanism and deformation in the Mojave Desert, although\ndetailed correlations await clarification of early Miocene reconstructions of the Tehachapi\nMountains. We then trace the post-20 Ma motion of the Mendocino slab window edge beneath\nthe Sierran-Great Valley block and find that it drifted steadily north, then stalled just north of\nSutter Buttes at ~4 Ma.", "isbn": "9780966586909", "publisher": "Bellwether Pub.", "place_of_publication": "Columbia, MD", "publication_date": "1998", "pages": "393-420" }, { "id": "authors:p8kan-vtn84", "collection": "authors", "collection_id": "p8kan-vtn84", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140415-080558763", "type": "book_section", "title": "Pliocene volcanogenic sedimentation along an accommodation zone in northeastern Baja California: The Puertecitos Formation", "book_title": "Pliocene carbonates and related facies flanking the Gulf of California, Baja California, Mexico", "author": [ { "family_name": "Mart\u00edn-Barajas", "given_name": "Arturo", "clpid": "Mart\u00edn-Barajas-A" }, { "family_name": "Tellez-Duarte", "given_name": "Miguel", "clpid": "Tellez-Duarte-M" }, { "family_name": "Stock", "given_name": "Joann M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" } ], "contributor": [ { "family_name": "Johnson", "given_name": "Markes E.", "clpid": "Johnson-M-E" }, { "family_name": "Ledesma-V\u00e1zquez", "given_name": "Jorge", "clpid": "Ledesma-V\u00e1zquez-J" } ], "abstract": "Accommodation zones on rift systems produce distinctive sedimentary facies and\nfacies architecture. The Puertecitos volcanic province in the northern Gulf Extensional\nProvince comprises an accommodation zone and records marine sedimentation\nand explosive volcanism during upper Miocene and early Pliocene time. The\nvolcano-sedimentary sequence consists of two \u00b7westward-thinning, wedge-shaped\ntransgressive-regressive marine sequences, each less than 100 m thick, separated by\none large pyroclastic flow unit. Northward the lower member is separated from the\nupper member by an angular unconformity and/or an interval of subaerial erosion.\nTo the southeast, the volcanic units dominate the stratigraphic sections, whereas\nnorthward the two marine sequences dominate and contain the distal volcaniclastic\nfacies. We propose the name of Puertecitos Formation to formally name this volcanosedimentary\nsequence.\nThe sedimentary facies crop out in subparallel narrow belts along the present\nrange front to the east of the volcanic province. The fossil assemblages and the sedimentary\nfacies show that this area was a tide-dominated marine embayment and\nalluvial plain, deepening to the east. Although the environment is favorable for the\nformation of bioclastic carbonates, the section is essentially devoid of significant carbonate\ndeposits. Instead, the basin was filled with epiclastic and pyroclastic material,\nand individual volcanic units occur as both subaerial and submarine facies and provide\nexcellent chronostratigraphic markers.\nIsostatic sea-level changes and volcaniclastic deposits had a major impact on the\nfacies distribution. Sediment accumulation rates were low. Pre- and postsedimentary\ndeformation was produced by an evenly distributed array of normal faults with small\nindividual offset. This fault pattern produced local facies variations and a distinct\nfacies architecture that contrasts with sedimentary facies associated with basins on\nrift segments to the north and elsewhere in the Gulf Extensional Province, where\nrapid subsidence and coarse-grained deposits are associated with large vertical separation\non basin-bounding faults.", "doi": "10.1130/0-8137-2318-3.1", "isbn": "9780813723181", "publisher": "Geological Society of America", "place_of_publication": "Boulder, CO", "publication_date": "1997", "pages": "1-24" }, { "id": "authors:ebnky-vdv22", "collection": "authors", "collection_id": "ebnky-vdv22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141020-082122032", "type": "book_section", "title": "Plate Tectonics", "book_title": "Encyclopedia of Applied Physics", "author": [ { "family_name": "Stock", "given_name": "Joann M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" } ], "abstract": "Earthquakes, volcanoes, active faults, and\nmountains tend to occur in long, linear belts\non the Earth's surface, bounding large\nregions that are relatively quiescent. The theory\nof plate tectonics views the quiescent\nregions as rigid \"plates\" and these deformational features, located at the boundaries between\nthe plates, as the inevitable consequences\nof relative motion among the plates.\nSince the plates are confined to the surface\nof a spherical Earth, their relative motion is\ngeometrically constrained. The great power\nof plate-tectonic theory lies in its ability to provide testable kinematic predictions regarding\nthe expected direction and rate of\nmotion at the boundaries between the plates.\nIn addition, it provides a framework for interpreting\npast geological events in terms of\nplate-tectonic processes observable today.\nSection 1 of this article describes the geometrical\naspects of motion of rigid plates on\na sphere, and presents rates and directions\nof motion between major plates, as determined\nfrom the relevant data. Section 2 describes\nthe differences between continental\nand oceanic parts of plates, constraints on\nplate thickness, and the vertical variations of\ntemperature and strength within the plates.\nSection 3 describes the elastic behavior of\nplates, isostasy, and rebound due to viscous\nflow beneath the plates. Section 4 discusses\nplate motions as an indication of processes\nat greater depths in the earth. Finally, Sec. 5\ndiscusses some of the limitations of plate-tectonic\ntheory.", "isbn": "3-527-28136-3", "publisher": "VCH Publishers", "place_of_publication": "New York, NY", "publication_date": "1996", "pages": "273-295" }, { "id": "authors:eazvz-bms77", "collection": "authors", "collection_id": "eazvz-bms77", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140410-142453767", "type": "book_section", "title": "Early Rift Sedimentation and Structure along the NE Margin of Baja California", "author": [ { "family_name": "Stock", "given_name": "Joann M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Mart\u00edn-Barajas", "given_name": "Arturo", "clpid": "Mart\u00edn-Barajas-A" }, { "family_name": "Tellez-Duarte", "given_name": "Miguel", "clpid": "Tellez-Duarte-M" } ], "contributor": [ { "family_name": "Abbott", "given_name": "Patrick L.", "clpid": "Abbott-P-L" }, { "family_name": "Cooper", "given_name": "John D.", "clpid": "Cooper-J-D" } ], "abstract": "This field trip will examine deposits and structures\nin four basins of NE Baja California which\nformed during Neogene rifting in the Gulf of California\nExtensional Province (Fig. 1). Our objective\nis to provide an overview of depositional environments\nand facies, and tectonic controls on the basin\nevolution, as a guide to interpreting early rift basins\nelsewhere around the Gulf of California as well as at\nother incipient oceanic rifts. The basins we will visit\nrange in age from middle Miocene (the continental\ndeposits of the Santa Rosa basin) to late Miocene\n(upper part of the Santa Rosa basin, and the San\nFelipe marine sequence) to Pliocene (San Felipe\nmarine sequence, Puertecitos Formation, and\nLaguna Salada sequence). They include both marine\nand nonmarine deposits, and record variations\nin sedimentation rate and tectonic patterns that are\nregionally important in the thermal and structural\nevolution of the northern Gulf of California. They\nalso lie in different structural settings within the rift\nsystem.", "publisher": "American Association of Petroleum Geologists, Pacific Section", "publication_date": "1996" }, { "id": "authors:vd5w1-px403", "collection": "authors", "collection_id": "vd5w1-px403", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141017-131317374", "type": "book_section", "title": "Estratigraf\u00eda y Petrolog\u00eda de la Secuencia Volc\u00e1nica de Puertecitos, Noreste de Baja California. Transici\u00f3n de un Arco Volc\u00e1nico a Rift", "author": [ { "family_name": "Mart\u00edn-Barajas", "given_name": "Arturo", "clpid": "Mart\u00edn-Barajas-A" }, { "family_name": "Stock", "given_name": "Joann M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" } ], "contributor": [ { "family_name": "Delgado-Argote", "given_name": "Luis A.", "clpid": "Delgado-Argote-L-A" }, { "family_name": "Mart\u00edn-Barajas", "given_name": "Arturo", "clpid": "Mart\u00edn-Barajas-A" } ], "abstract": "En la Provincia Volc\u00e1nica de Puertecitos (PVP), en el NE de Baja California, una sucesi\u00f3n de dep\u00f3sitos\npirocl\u00e1sticos y lavas riol\u00edticas de la etapa temprana del rift del Golfo de California (Mioceno Tard\u00edo-Plioceno)\nsobreyace en discordancia a rocas andes\u00edticas atribuidas al arco volcanico del Mioceno (Tma). En la franja oriental\nde la PVP se han documentado dos per\u00edodos de actividad volc\u00e1nica contempor\u00e1neos al desarrollo del rift: uno a\nfines del Mioceno Tard\u00edo (ca. 6 Ma) y otro en el Plioceno Temprano (ca. 3 Ma). El primero incluye una secuencia\nde ignimbritas (Tobas El Canelo, Tmec) de m\u00e1s de 300 m de espesor contenida entre dos per\u00edodos efusivos de\ndomos riol\u00edticos. Los cambios de espesor de estas ignimbritas (Tmec), indican que su fuente est\u00e1 localizada hacia\nel NW de la zona de estudio, mientras que las coladas riol\u00edticas son locales y forman una serie de domos sobrepuestos\norientados N-S, en la misma direcci\u00f3n del fallamiento. A fines del Plioceno Temprano un segundo per\u00edodo de\nactividad explosiva produjo una serie de flujos pirocl\u00e1sticos de composici\u00f3n riol\u00edtica y dac\u00edtica (Tpr). Este paquete\nincluye hacia la costa central m\u00e1s de 20 unidades de dep\u00f3sito, con un espesor superior a 200 m que disminuye\nhacia el W y NNE, sugieriendo que la fuente de Tpr se encontraba al E de la costa actual. Hacia el norte, algunas\nunidades de Tpr se hallan interestratificadas con dep\u00f3sitos marinas someros del Plioceno Temprano. Este per\u00edodo\nculmin\u00f3 con la erupci\u00f3n del Volc\u00e1n Prieto (monogen\u00e9tico) y derrames fisurales de composici\u00f3n andes\u00edtica durante\nel Plioceno Tard\u00edo y Pleistoceno.\nLas andesitas asociadas al rift en los dos per\u00edodos de actividad volc\u00e1nica son comparativamente de escaso\nvolumen, y se caracterizan por el bajo contenido de K_2O y contenidos variables de TiO_2 y MgO con relaci\u00f3n a las\nandesitas y basaltos asociados al arco volc\u00e1nico del Mioceno. La caracter\u00edstica com\u00fan de las andesitas y las riolitas\nes la asociaci\u00f3n clinopiroxeno-ortopiroxeno (y olivino en algunos casos), y bajo o nulo contenido de biotita,\nhornblenda, feldespato alcalino y cuarzo. Lo anterior sugiere una mezcla de magmas, uno m\u00e1fico a alta temperatura\ny con posible afinidad tole\u00edtica, y otro m\u00e1s diferenciado y frio posiblemente formado por material de la corteza.\nLa generaci\u00f3n del magmatismo est\u00e1 asociado a la tect\u00f3nica transtensional, que en el NE de la PVP se manifiesta\ncon una extensi\u00f3n en direcci\u00f3n ESE a ENE durante el Mioceno Tard\u00edo - Plioceno.", "publisher": "Uni\u00f3n Geof\u00edsica Mexicana", "publication_date": "1993" }, { "id": "authors:nr4rf-tt063", "collection": "authors", "collection_id": "nr4rf-tt063", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140909-100119572", "type": "book_section", "title": "Miocene to Holocene Extensional Tectonics and Volcanic Stratigraphy of NE Baja California, Mexico", "author": [ { "family_name": "Stock", "given_name": "Joann M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Mart\u00edn", "given_name": "Arturo B.", "clpid": "Mart\u00edn-A-B" }, { "family_name": "Su\u00e1rez", "given_name": "Francisco V.", "clpid": "Su\u00e1rez-F-V" }, { "family_name": "Miller", "given_name": "M. Meghan", "clpid": "Miller-M-M" } ], "contributor": [ { "family_name": "Walawender", "given_name": "Michael J.", "clpid": "Walawender-M-J" }, { "family_name": "Hanan", "given_name": "Barry B.", "clpid": "Hanan-B-B" } ], "abstract": "Northeastern Baja California presently experiences\nactive extensional and strike-slip faulting related to the\ntranstensive Pacific-North America plate boundary in\nthe Gulf of California. Some of the active structures\nare fairly new, whereas others appear to have a\nmovement history as far back as Miocene time. This\ntrip focuses on the history of Miocene to Recent\nextension, and its relation to the development of the\nPacific-North America plate boundary, in the Gulf\nExtensional Province of NE Baja California. We will\nsee the extensional structures at the latitudes of San\nFelipe to Puertecitos, and view the stratigraphic\nrelationships of the volcanic and marine rocks that\nconstrain the timing of this extension. Several major\nstructural features are well-exposed here: the Main\nGulf Escarpment and its structural variations along\nstrike; the E-W variations in extensional styles within\nthe extensional province; the extreme narrowing of the\nGulf Extensional Province near El Huerfanito; and\nevidence for variations in timing and amount of\nextension throughout the extensional province.", "publisher": "San Diego State University", "publication_date": "1991" }, { "id": "authors:94j7x-3zp56", "collection": "authors", "collection_id": "94j7x-3zp56", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140922-155549744", "type": "book_section", "title": "Stress Field at Yucca Mountain, Nevada", "author": [ { "family_name": "Stock", "given_name": "Joann M.", "orcid": "0000-0003-4816-7865", "clpid": "Stock-J-M" }, { "family_name": "Healy", "given_name": "John H.", "clpid": "Healy-J-H" } ], "contributor": [ { "family_name": "Carr", "given_name": "Michael D.", "clpid": "Carr-M-D" }, { "family_name": "Yount", "given_name": "J. C.", "clpid": "Yount-J-C" } ], "abstract": "Hydraulic fracturing stress measurements performed in four\nholes (USW G-1, USW G-2, USW G-3, and Ue25P1) indicate\nthat at Yucca Mountain, the least horizontal stress S_h is less than\nthe vertical stress S_v. Values of the greatest horizontal stress S_H\nare intermediate between S_h and S_v, corresponding to a normal\nfaulting regime with values of \u03a6 = (S_H-S_h)/(S_v-S_h) between\n0.25 and 0.7. Drilling-induced hydraulic fractures seen on\nborehole televiewer logs indicate an S_h direction of N. 60\u00b0 W.\nto N. 65\u00b0 W. in USW G-1, USW G-2, and USW G-3. The same\nS_h direction is inferred from breakout orientations in USW G-2\nand Ue25P1. The S_h values in the upper parts of the three USW\nG holes are less than the pressure of a column of water filling\nthe borehole to the surface. Thus, the long drilling-induced\nhydraulic fractures in the shallow parts of these holes could have\nbeen formed in attempts to maintain circulation during drilling.\nThese low S_h values may be intimately related to the low water\ntable and fracture-dominated hydrology of Yucca Mountain.", "publisher": "U.S. Geological Survey", "publication_date": "1988" } ]