Integrated Sr isotope variations and sea-level history of Middle to Upper Cambrian platform carbonates: Implications for the evolution of Cambrian seawater 87Sr/86Sr

Research Article| October 01, 1996 Integrated Sr isotope variations and sea-level history of Middle to Upper Cambrian platform carbonates: Implications for the evolution of Cambrian seawater 87Sr/86Sr Isabel P. Montañez; Isabel P. Montañez 1Department of Geological Sciences, University of Texas, Austin, Texas 78712 Search for other works by this author on: GSW Google Scholar Jay L. Banner; Jay L. Banner 2Department of Earth Sciences, University of California, Riverside, California, 92521 Search for other works by this author on: GSW Google Scholar David A. Osleger; David A. Osleger 1Department of Geological Sciences, University of Texas, Austin, Texas 78712 Search for other works by this author on: GSW Google Scholar Lars E. Borg; Lars E. Borg 2Department of Earth Sciences, University of California, Riverside, California, 92521 Search for other works by this author on: GSW Google Scholar Paula J. Bosserman Paula J. Bosserman 3Department of Soil and Environmental Sciences, University of California, Riverside, California 92521 Search for other works by this author on: GSW Google Scholar Author and Article Information Isabel P. Montañez 1Department of Geological Sciences, University of Texas, Austin, Texas 78712 Jay L. Banner 2Department of Earth Sciences, University of California, Riverside, California, 92521 David A. Osleger 1Department of Geological Sciences, University of Texas, Austin, Texas 78712 Lars E. Borg 2Department of Earth Sciences, University of California, Riverside, California, 92521 Paula J. Bosserman 3Department of Soil and Environmental Sciences, University of California, Riverside, California 92521 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1996) 24 (10): 917–920. https://doi.org/10.1130/0091-7613(1996)024<0917:ISIVAS>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Isabel P. Montañez, Jay L. Banner, David A. Osleger, Lars E. Borg, Paula J. Bosserman; Integrated Sr isotope variations and sea-level history of Middle to Upper Cambrian platform carbonates: Implications for the evolution of Cambrian seawater 87Sr/86Sr. Geology 1996;; 24 (10): 917–920. doi: https://doi.org/10.1130/0091-7613(1996)024<0917:ISIVAS>2.3.CO;2 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 SocietyGeology Search Advanced Search Abstract A high-resolution Sr isotope study of Middle to Upper Cambrian platform carbonates of the southern Great Basin significantly refines the structure of the existing seawater Sr isotope curve. Samples were selected using rigorous stratigraphic, petrographic, and geochemical criteria in order to minimize the effects of diagenetic alteration and contamination from noncarbonate components. Highest seawater 87Sr/86Sr values over the past 2 b.y. are constrained to <0.7093 and occurred during the latest Middle Cambrian to earliest Late Cambrian. Integrated with published Cambrian seawater 87Sr/86Sr values, these new data record the culmination of an increasing trend in seawater 87Sr/86Sr beginning in Early Cambrian time. This trend is interpreted to reflect increasing flux and/or isotopic ratio of riverine Sr delivered to Cambrian oceans in response to Pan-African orogenesis and attendant enhanced chemical weathering. High-resolution changes in seawater 87Sr/86Sr values are superimposed on the longer-term trend. Correlation between 87Sr/86Sr values and sea level leads us to propose a model that links changes in weathering rates and riverine Sr flux with variations in exposed continental surface area related to short-term (1–5 m.y.) sea-level events during greenhouse times. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.