Multiphase flow of the late Wisconsinan Cordilleran ice sheet in western Canada

Abstract

Research Article| December 01, 2000 Multiphase flow of the late Wisconsinan Cordilleran ice sheet in western Canada Andrew J. Stumpf; Andrew J. Stumpf 1Quaternary and Environmental Studies Group, Department of Geology, University of New Brunswick, P.O. Box 4400, Fredericton, New Brunswick E3B 5A3, Canada Search for other works by this author on: GSW Google Scholar Bruce E. Broster; Bruce E. Broster 1Quaternary and Environmental Studies Group, Department of Geology, University of New Brunswick, P.O. Box 4400, Fredericton, New Brunswick E3B 5A3, Canada Search for other works by this author on: GSW Google Scholar Victor M. Levson Victor M. Levson 2British Columbia Ministry of Energy and Mines, Geological Survey Branch, P.O. Box 9320 STN PROV GOVT, Victoria, British Columbia V8W 9N3, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information Andrew J. Stumpf 1Quaternary and Environmental Studies Group, Department of Geology, University of New Brunswick, P.O. Box 4400, Fredericton, New Brunswick E3B 5A3, Canada Bruce E. Broster 1Quaternary and Environmental Studies Group, Department of Geology, University of New Brunswick, P.O. Box 4400, Fredericton, New Brunswick E3B 5A3, Canada Victor M. Levson 2British Columbia Ministry of Energy and Mines, Geological Survey Branch, P.O. Box 9320 STN PROV GOVT, Victoria, British Columbia V8W 9N3, Canada Publisher: Geological Society of America Received: 19 Jul 1999 Revision Received: 07 Feb 2000 Accepted: 09 Feb 2000 First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2000) 112 (12): 1850–1863. https://doi.org/10.1130/0016-7606(2000)112<1850:MFOTLW>2.0.CO;2 Article history Received: 19 Jul 1999 Revision Received: 07 Feb 2000 Accepted: 09 Feb 2000 First Online: 01 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 Andrew J. Stumpf, Bruce E. Broster, Victor M. Levson; Multiphase flow of the late Wisconsinan Cordilleran ice sheet in western Canada. GSA Bulletin 2000;; 112 (12): 1850–1863. doi: https://doi.org/10.1130/0016-7606(2000)112<1850:MFOTLW>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 SocietyGSA Bulletin Search Advanced Search Abstract In central British Columbia, ice flow during the late Wisconsinan Fraser glaciation (ca. 25–10 ka) occurred in three phases. The ice expansion phase occurred during an extended period when glaciers flowed westward to the Pacific Ocean and east-southeastward onto the Nechako Plateau from ice centers in the Skeena, Hazelton, Coast, and Omineca Mountains. Initially, glacier flow was confined by topography along major valleys, but eventually piedmont and montane glaciers coalesced to form an integrated glacier system, the Cordilleran ice sheet. In the maximum phase, a Cordilleran ice divide developed over the Nechako Plateau to 300 km inland from the Pacific coast. At this time, the surface of the ice sheet extended well above 2500 m above sea level, and flowed westward over the Skeena, Hazelton, and Coast Mountains onto the continental shelf, and eastward across the Rocky Mountains into Alberta. In the late glacial phase, a rapid rise of the equilibrium line caused ice lobes to stagnate in valleys, and restricted accumulation centers to high mountains.Discordant directions in ice flow are attributed to fluctuations of the ice divide representing changes in the location of accumulation centers and ice thickness. Ice centers probably shifted in response to climate, irregular growth in the ice sheet, rapid calving, ice streaming, and drainage of proglacial and subglacial water bodies. Crosscutting ice-flow indicators and preservation of early (valley parallel) flow features in areas exposed to later (cross-valley) glacier erosion indicate that the ice expansion phase was the most erosive and protracted event. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.