Long-lived glaciation in the Late Ordovician? Isotopic and sequence-stratigraphic evidence from western Laurentia

Abstract

Research Article| February 01, 2005 Long-lived glaciation in the Late Ordovician? Isotopic and sequence-stratigraphic evidence from western Laurentia Matthew R. Saltzman; Matthew R. Saltzman 1Department of Geological Sciences, Ohio State University, Columbus, Ohio 43210, USA Search for other works by this author on: GSW Google Scholar Seth A. Young Seth A. Young 1Department of Geological Sciences, Ohio State University, Columbus, Ohio 43210, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Matthew R. Saltzman 1Department of Geological Sciences, Ohio State University, Columbus, Ohio 43210, USA Seth A. Young 1Department of Geological Sciences, Ohio State University, Columbus, Ohio 43210, USA Publisher: Geological Society of America Received: 23 Jun 2004 Revision Received: 06 Oct 2004 Accepted: 10 Oct 2004 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2005) 33 (2): 109–112. https://doi.org/10.1130/G21219.1 Article history Received: 23 Jun 2004 Revision Received: 06 Oct 2004 Accepted: 10 Oct 2004 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 Matthew R. Saltzman, Seth A. Young; Long-lived glaciation in the Late Ordovician? Isotopic and sequence-stratigraphic evidence from western Laurentia. Geology 2005;; 33 (2): 109–112. doi: https://doi.org/10.1130/G21219.1 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 SocietyGeology Search Advanced Search Abstract The timing and causes of the transition to an icehouse climate in the Late Ordovician are controversial. Results of an integrated δ13C and sequence stratigraphic analysis in Nevada show that in the Late Ordovician Chatfieldian Stage (mid-Caradoc) a positive δ13C excursion in the upper part of the Copenhagen Formation was closely followed by a regressive event evidenced within the prominent Eureka Quartzite. The Chatfieldian δ13C excursion is known globally and interpreted to record enhanced organic carbon burial, which lowered atmospheric pCO2 to levels near the threshold for ice buildup in the Ordovician greenhouse climate. The subsequent regressive event in central Nevada, previously interpreted as part of a regional tectonic adjustment, is here attributed in part to sea-level drawdown from the initiation of continental glaciation on Gondwana. This drop in sea level—which may have contributed to further cooling through a reduction in poleward heat transport and a lowering of pCO2 by suppressing shelf-carbonate production—signals the transition to a Late Ordovician icehouse climate ∼10 m.y. before the widespread Hirnantian glacial maximum at the end of the Ordovician. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.