A hot and high Eocene Sierra Nevada

Abstract

Research Article| March 01, 2016 A hot and high Eocene Sierra Nevada Hari T. Mix; Hari T. Mix † 1Department of Environmental Studies and Sciences, Santa Clara University, Santa Clara, California 95053, USA2Department of Earth System Science, Stanford University, Stanford, California 94305, USA †hmix@scu.edu Search for other works by this author on: GSW Google Scholar Daniel E. Ibarra; Daniel E. Ibarra 2Department of Earth System Science, Stanford University, Stanford, California 94305, USA Search for other works by this author on: GSW Google Scholar Andreas Mulch; Andreas Mulch 3Senckenberg Biodiversity and Climate Research Centre (BiK-F), 60325 Frankfurt/Main, Germany4Institut für Geowissenschaften, Goethe Universität Frankfurt, 60438 Frankfurt/Main, Germany5Senckenberg Research Institutes and Natural History Museums, Senckenberganlage 25, 60325 Frankfurt/Main, Germany Search for other works by this author on: GSW Google Scholar Stephan A. Graham; Stephan A. Graham 6Department of Geological Sciences, Stanford University, Stanford, California 94305, USA Search for other works by this author on: GSW Google Scholar C. Page Chamberlain C. Page Chamberlain 2Department of Earth System Science, Stanford University, Stanford, California 94305, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Hari T. Mix † 1Department of Environmental Studies and Sciences, Santa Clara University, Santa Clara, California 95053, USA2Department of Earth System Science, Stanford University, Stanford, California 94305, USA Daniel E. Ibarra 2Department of Earth System Science, Stanford University, Stanford, California 94305, USA Andreas Mulch 3Senckenberg Biodiversity and Climate Research Centre (BiK-F), 60325 Frankfurt/Main, Germany4Institut für Geowissenschaften, Goethe Universität Frankfurt, 60438 Frankfurt/Main, Germany5Senckenberg Research Institutes and Natural History Museums, Senckenberganlage 25, 60325 Frankfurt/Main, Germany Stephan A. Graham 6Department of Geological Sciences, Stanford University, Stanford, California 94305, USA C. Page Chamberlain 2Department of Earth System Science, Stanford University, Stanford, California 94305, USA †hmix@scu.edu Publisher: Geological Society of America Received: 03 Feb 2015 Revision Received: 14 Jul 2015 Accepted: 09 Sep 2015 First Online: 09 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2015 Geological Society of America GSA Bulletin (2016) 128 (3-4): 531–542. https://doi.org/10.1130/B31294.1 Article history Received: 03 Feb 2015 Revision Received: 14 Jul 2015 Accepted: 09 Sep 2015 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Hari T. Mix, Daniel E. Ibarra, Andreas Mulch, Stephan A. Graham, C. Page Chamberlain; A hot and high Eocene Sierra Nevada. GSA Bulletin 2016;; 128 (3-4): 531–542. doi: https://doi.org/10.1130/B31294.1 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 Despite broad interest in determining the topographic and climatic histories of mountain ranges, the evolution of California’s Sierra Nevada remains actively debated. Prior stable isotope–based studies of the Sierra Nevada have relied primarily on hydrogen isotopes in kaolinite, hydrated volcanic glass, and leaf n-alkanes. Here, we reconstruct the temperature and elevation of the early Eocene Sierra Nevada using the oxygen isotope composition of kaolinitized granite clasts from the ancestral Yuba and American Rivers that drained the windward (Pacific) flank of the Sierra Nevada. First, we evaluated the possible contributions of hydrogen isotope exchange in kaolinite by direct comparison with oxygen isotope measurements. Next, we utilized differences in the hydrogen and oxygen isotope fractionation in kaolinite to constrain early Eocene midlatitude weathering temperatures. Oxygen isotope geochemistry of in situ kaolinites indicates upstream (eastward) depletion of 18O in the northern Sierra Nevada. The δ18O values, ranging from 11.4‰ to 14.4‰ at the easternmost localities, correspond to paleoelevations as high as 2400 m when simulating the orographic precipitation of moisture from a Pacific source using Eocene boundary conditions. This result is consistent with prior hydrogen isotope studies of the northern Sierra, but oxygen isotope–based paleoelevation estimates are systematically ∼500–1000 m higher than those from hydrogen-based estimates from the same samples. Kaolinite geothermometry from 16 samples produced early Eocene weathering temperatures of 13.0–36.7 °C, with an average of 23.2 ± 6.4 °C (1σ). These kaolinite temperature reconstructions are in general agreement with paleofloral and geochemical constraints from Eocene California localities and climate model simulations. Our results confirm prior hydrogen isotope–based paleoelevation estimates and further substantiate the existence of a hot and high Eocene Sierra Nevada. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.