Deforming bed conditions associated with a major ice stream of the last British ice sheet

Abstract

Research Article| September 01, 2001 Deforming bed conditions associated with a major ice stream of the last British ice sheet Colm Ó Cofaigh; Colm Ó Cofaigh 1Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK Search for other works by this author on: GSW Google Scholar David J.A. Evans David J.A. Evans 2Department of Geography and Topographic Science, University of Glasgow, Glasgow G12 8QQ, UK Search for other works by this author on: GSW Google Scholar Geology (2001) 29 (9): 795–798. https://doi.org/10.1130/0091-7613(2001)029<0795:DBCAWA>2.0.CO;2 Article history received: 14 Feb 2001 rev-recd: 17 Apr 2001 accepted: 07 May 2001 first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Colm Ó Cofaigh, David J.A. Evans; Deforming bed conditions associated with a major ice stream of the last British ice sheet. Geology 2001;; 29 (9): 795–798. doi: https://doi.org/10.1130/0091-7613(2001)029<0795:DBCAWA>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 The Irish Sea ice stream was the largest ice stream to drain the last British ice sheet, and around the margins of the Celtic Sea it deposited a shelly diamict facies that has been variously interpreted as subglacial till or distal glacial marine mud. We present new observations on the sedimentology of the shelly diamict and overlying sediments from the south coast of Ireland, and demonstrate that the shelly diamict facies is a subglacial deformation till deposited during onshore movement of a grounded Irish Sea ice stream. Stratigraphic and chronological data indicate that this occurred during the last glaciation, and this is regionally consistent with marine geological evidence from the Celtic Sea. We propose that the deforming bed tills along the south coast of Ireland are the onshore record of a rapid advance of an unstable Irish Sea ice stream into the Celtic Sea. This advance was facilitated, at least in part, by a saturated substrate of readily deformable, fine-grained, marine sediment. This implies an unstable and dynamic Irish Sea ice stream during oxygen isotope stage 2, and therefore extension of the last British ice sheet into the Celtic Sea far south of its traditionally interpreted limits. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.