Geomorphological evidence and cosmogenic 10Be/26Al exposure ages for the Last Glacial Maximum and deglaciation of the Antarctic Peninsula Ice Sheet

Abstract

Research Article| September 01, 2006 Geomorphological evidence and cosmogenic 10Be/26Al exposure ages for the Last Glacial Maximum and deglaciation of the Antarctic Peninsula Ice Sheet Michael J. Bentley; Michael J. Bentley 1Department of Geography, University of Durham, South Road, Durham DH1 3LE, UK Search for other works by this author on: GSW Google Scholar Christopher J. Fogwill; Christopher J. Fogwill 2Institute of Geography, School of Geosciences, University of Edinburgh, Drummond Street, Edinburgh EH8 9XP, UK Search for other works by this author on: GSW Google Scholar Peter W. Kubik; Peter W. Kubik 3Paul Scherrer Institut, c/o Institute of Particle Physics, ETH Zürich, 8093 Zürich, Switzerland Search for other works by this author on: GSW Google Scholar David E. Sugden David E. Sugden 4School of Geosciences, University of Edinburgh, Grant Institute, Kings Buildings, West Mains Road, Edinburgh EH9 3JW, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Michael J. Bentley 1Department of Geography, University of Durham, South Road, Durham DH1 3LE, UK Christopher J. Fogwill 2Institute of Geography, School of Geosciences, University of Edinburgh, Drummond Street, Edinburgh EH8 9XP, UK Peter W. Kubik 3Paul Scherrer Institut, c/o Institute of Particle Physics, ETH Zürich, 8093 Zürich, Switzerland David E. Sugden 4School of Geosciences, University of Edinburgh, Grant Institute, Kings Buildings, West Mains Road, Edinburgh EH9 3JW, UK Publisher: Geological Society of America Received: 28 Sep 2004 Revision Received: 22 Jul 2005 Accepted: 24 Mar 2006 First Online: 08 Mar 2017 Online Issn: 1943-2674 Print Issn: 0016-7606 Geological Society of America GSA Bulletin (2006) 118 (9-10): 1149–1159. https://doi.org/10.1130/B25735.1 Article history Received: 28 Sep 2004 Revision Received: 22 Jul 2005 Accepted: 24 Mar 2006 First Online: 08 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 Michael J. Bentley, Christopher J. Fogwill, Peter W. Kubik, David E. Sugden; Geomorphological evidence and cosmogenic 10Be/26Al exposure ages for the Last Glacial Maximum and deglaciation of the Antarctic Peninsula Ice Sheet. GSA Bulletin 2006;; 118 (9-10): 1149–1159. doi: https://doi.org/10.1130/B25735.1 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 This paper presents the first systematic attempt to map the Last Glacial Maximum (LGM) configuration of the southern and central parts of the Antarctic Peninsula Ice Sheet, and to determine the timing of onshore ice-sheet retreat. Geomorphologic evidence shows that the LGM ice sheet expanded to form two ice domes in Palmer Land and merged with an expanded and thicker West Antarctic Ice Sheet in the Weddell Sea. Ice from the Antarctic Peninsula merged with Alexander Island ice in George VI Sound. Cosmogenic 10Be and 26Al data from 29 erratics on nunataks yield model ages between 7.2 ka and older than 1 Ma. The data set contains a high proportion of erratics with evidence of nuclide inheritance. Once these ages have been excluded, the cosmogenic ages suggest that thinning of the west side of the Antarctic Peninsula Ice Sheet to near-present configuration was almost complete by the early Holocene. These data, combined with previously published 14C data, exclude the possibility that the west side of the Antarctic Peninsula Ice Sheet has been thinning throughout the Holocene, as has been demonstrated for some other sectors of the West Antarctic Ice Sheet. On the east side of the Antarctic Peninsula, ice-sheet thinning was under way prior to the early Holocene, but our data do not constrain the ice-sheet behavior more recently than 7.2 ka. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.