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Oceanic magmatism in sedimentary basins of the northern Gulf of California rift

2013; Geological Society of America; Volume: 125; Issue: 11-12 Linguagem: Inglês

10.1130/b30787.1

1943-2674

Axel K. Schmitt, A. Martin, Bodo Weber, Daniel F. Stöckli, Haibo Zou, Chuan‐Chou Shen,

Geological formations and processes

Research Article| November 01, 2013 Oceanic magmatism in sedimentary basins of the northern Gulf of California rift Axel K. Schmitt; Axel K. Schmitt † 1Department of Earth and Space Sciences, University of California–Los Angeles, Los Angeles, California 90095-1567, USA †E-mail: axelk@argon.ess.ucla.edu Search for other works by this author on: GSW Google Scholar Arturo Martín; Arturo Martín 2Departamento de Geología, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Ensenada–Tijuana No. 3918, Zona Playitas, Ensenada, B.C., C.P. 22800, México Search for other works by this author on: GSW Google Scholar Bodo Weber; Bodo Weber 2Departamento de Geología, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Ensenada–Tijuana No. 3918, Zona Playitas, Ensenada, B.C., C.P. 22800, México Search for other works by this author on: GSW Google Scholar Daniel F. Stockli; Daniel F. Stockli 3Department of Geological Sciences, University of Texas at Austin, EPS RM 1.130, 1 University Station C9000, Austin, Texas 78712-0254, USA Search for other works by this author on: GSW Google Scholar Haibo Zou; Haibo Zou 4Department of Geology and Geography, Auburn University, 210 Petrie Hall, Auburn, Alabama 36849-5305, USA Search for other works by this author on: GSW Google Scholar Chuan-Chou Shen Chuan-Chou Shen 5High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan, R.O.C Search for other works by this author on: GSW Google Scholar Author and Article Information Axel K. Schmitt † 1Department of Earth and Space Sciences, University of California–Los Angeles, Los Angeles, California 90095-1567, USA Arturo Martín 2Departamento de Geología, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Ensenada–Tijuana No. 3918, Zona Playitas, Ensenada, B.C., C.P. 22800, México Bodo Weber 2Departamento de Geología, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Ensenada–Tijuana No. 3918, Zona Playitas, Ensenada, B.C., C.P. 22800, México Daniel F. Stockli 3Department of Geological Sciences, University of Texas at Austin, EPS RM 1.130, 1 University Station C9000, Austin, Texas 78712-0254, USA Haibo Zou 4Department of Geology and Geography, Auburn University, 210 Petrie Hall, Auburn, Alabama 36849-5305, USA Chuan-Chou Shen 5High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan, R.O.C †E-mail: axelk@argon.ess.ucla.edu Publisher: Geological Society of America Received: 28 Aug 2012 Revision Received: 25 May 2013 Accepted: 07 Aug 2013 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2013 Geological Society of America GSA Bulletin (2013) 125 (11-12): 1833–1850. https://doi.org/10.1130/B30787.1 Article history Received: 28 Aug 2012 Revision Received: 25 May 2013 Accepted: 07 Aug 2013 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Axel K. Schmitt, Arturo Martín, Bodo Weber, Daniel F. Stockli, Haibo Zou, Chuan-Chou Shen; Oceanic magmatism in sedimentary basins of the northern Gulf of California rift. GSA Bulletin 2013;; 125 (11-12): 1833–1850. doi: https://doi.org/10.1130/B30787.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Rift-related magmatism in the northernmost Gulf of California and the adjacent subaerial Salton Trough and Cerro Prieto basins comprises intermediate to rhyolitic surficial and buried lava flows and domes, including their xenolith cargo. In addition, geothermal drill wells frequently penetrate subsurface gabbroic to granitic sills and dikes, which intruded into Colorado River delta fluviatile and lacustrine sediments. Combined single-crystal U-Th-Pb and (U-Th)/He zircon ages reveal late Pleistocene to Holocene eruption ages for three volcanic centers in adjacent rift basins (from N to S): Salton Buttes (eruption age: 2.48 ± 0.47 ka; 95% confidence), Cerro Prieto (maximum eruption age: 73 ± 7 ka), and Roca Consag (eruption age: 43 ± 6 ka). U-Th zircon and allanite crystallization ages are close to the eruption ages, with the exception of Roca Consag lava, the zircon population of which is dominated by zircon with ca. 1 Ma crystallization ages, a population interpreted to be recycled from an unknown crustal source underlying the Wagner basin. Nd isotopic ratios for subsurface microgabbros from Cerro Prieto (εNd = +8.9) overlap with values for mid-oceanic-ridge basalts (MORB) from the East Pacific Rise, adjacent to the southern Gulf of California. Cerro Prieto microgranites and Salton Sea basaltic xenoliths have similarly elevated εNd values. The lowest εNd value for late Pleistocene–Holocene igneous rocks from the northern Gulf of California is for Cerro Prieto dacitic lava (εNd = +0.6). This value implies minor (<20%) assimilation of continental crustal rocks, which, however, is an upper limit because of crystal-scale evidence for magma contamination by unconsolidated sediment at the time of eruption. Zircon crystals in felsic rocks (rhyolite lavas, intrusive microgranites, and granophyre xenoliths) have trace-element and submantle δ18O compositions that are robust indicators for a mafic source that has exchanged oxygen by interacting with meteoric hydrothermal fluids. Collectively, these data imply that oceanic rifting has initiated in the Salton Trough and Cerro Prieto basins. There, MORB-type magmas formed mafic intrusions within thick sedimentary basin fill, where they became exposed to deep-reaching hydrothermal fluids. Diverse intermediate- to high-silica rhyolitic magmas that are prevalent at the surface are produced by fractional crystallization of mafic parental magmas with minor assimilation of sediments or pre-rift basement rocks, and by partial melting of hydrothermally altered mafic intrusions. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.