Widespread, prolonged late Middle to Late Ordovician upwelling in North America: A proxy record of glaciation?

Abstract

Research Article| January 01, 2003 Widespread, prolonged late Middle to Late Ordovician upwelling in North America: A proxy record of glaciation? Michael C. Pope; Michael C. Pope 1Department of Geology, Washington State University, Pullman, Washington 99164-2812, USA Search for other works by this author on: GSW Google Scholar Jessica B. Steffen Jessica B. Steffen 1Department of Geology, Washington State University, Pullman, Washington 99164-2812, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Michael C. Pope 1Department of Geology, Washington State University, Pullman, Washington 99164-2812, USA Jessica B. Steffen 1Department of Geology, Washington State University, Pullman, Washington 99164-2812, USA Publisher: Geological Society of America Received: 08 Jun 2002 Revision Received: 16 Sep 2002 Accepted: 23 Sep 2002 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2003) 31 (1): 63–66. https://doi.org/10.1130/0091-7613(2003)031<0063:WPLMTL>2.0.CO;2 Article history Received: 08 Jun 2002 Revision Received: 16 Sep 2002 Accepted: 23 Sep 2002 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Michael C. Pope, Jessica B. Steffen; Widespread, prolonged late Middle to Late Ordovician upwelling in North America: A proxy record of glaciation?. Geology 2003;; 31 (1): 63–66. doi: https://doi.org/10.1130/0091-7613(2003)031<0063:WPLMTL>2.0.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 Late Middle to Late Ordovician subtidal ramp carbonates of New Mexico, Texas, and Oklahoma contain abundant spiculitic chert (to 70% chert by volume) and phosphate (1–5 wt%), indicating that these rocks formed in an extensive upwelling zone. Upwelling began in the late Middle Ordovician (ca. 454 Ma) and persisted until the end of the Ordovician. Late Ordovician cherty carbonates also occur along the U.S. Cordilleran margin, in board of organic-rich graptolitic shale and chert. The widespread occurrence of Late Ordovician cherty and phosphatic carbonates on southern and western Laurentia, in addition to phosphate-rich, cool-water carbonates over much of the North American Midcontinent, suggests vigorous thermohaline circulation related to prolonged (10–14 Ma) Gondwana glaciation. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.