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Subglacial carbonates constrain basal conditions and oxygen isotopic composition of the Laurentide Ice Sheet over Arctic Canada

2011; Geological Society of America; Volume: 40; Issue: 2 Linguagem: Inglês

10.1130/g32335.1

1943-2682

Kurt A. Refsnider, Gifford H. Miller, Claude Hillaire‐Marcel, Marilyn L. Fogel, Bassam Ghaleb, R. Bowden,

Climate change and permafrost

Research Article| February 01, 2012 Subglacial carbonates constrain basal conditions and oxygen isotopic composition of the Laurentide Ice Sheet over Arctic Canada Kurt A. Refsnider; Kurt A. Refsnider 1Institute of Arctic and Alpine Research (INSTAAR) and the Department of Geological Sciences, University of Colorado, Boulder, Colorado 80309, USA Search for other works by this author on: GSW Google Scholar Gifford H. Miller; Gifford H. Miller 1Institute of Arctic and Alpine Research (INSTAAR) and the Department of Geological Sciences, University of Colorado, Boulder, Colorado 80309, USA Search for other works by this author on: GSW Google Scholar Claude Hillaire-Marcel; Claude Hillaire-Marcel 2Centre GEOTOP, Université du Québec à Montréal, Montréal, Québec H3C 3P8, Canada Search for other works by this author on: GSW Google Scholar Marilyn L. Fogel; Marilyn L. Fogel 3Geophysical Laboratory, Carnegie Institute, Washington, D.C. 20015, USA Search for other works by this author on: GSW Google Scholar Bassam Ghaleb; Bassam Ghaleb 2Centre GEOTOP, Université du Québec à Montréal, Montréal, Québec H3C 3P8, Canada Search for other works by this author on: GSW Google Scholar Roxane Bowden Roxane Bowden 3Geophysical Laboratory, Carnegie Institute, Washington, D.C. 20015, USA Search for other works by this author on: GSW Google Scholar Geology (2012) 40 (2): 135–138. https://doi.org/10.1130/G32335.1 Article history received: 08 Apr 2011 rev-recd: 13 Sep 2011 accepted: 15 Sep 2011 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 Kurt A. Refsnider, Gifford H. Miller, Claude Hillaire-Marcel, Marilyn L. Fogel, Bassam Ghaleb, Roxane Bowden; Subglacial carbonates constrain basal conditions and oxygen isotopic composition of the Laurentide Ice Sheet over Arctic Canada. Geology 2012;; 40 (2): 135–138. doi: https://doi.org/10.1130/G32335.1 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 Subglacially precipitated carbonate crusts (SPCCs) formed on bedrock and till boulder surfaces adjacent to the Barnes Ice Cap (BIC), central Baffin Island, Arctic Canada, act as unique archives of Laurentide Ice Sheet basal conditions. Uranium-series dating of these features reveals that carbonate precipitation from subglacial meltwater occurred during the Last Glacial Maximum (LGM), requiring warm-based ice in the region at that time. However, the preservation of fragile SPCCs is unlikely beneath erosive warm-based ice, suggesting that the transition to subsequent cold-based conditions took place shortly after the LGM, and glacial erosion in the region occurred dominantly prior to the LGM. The oxygen isotopic composition of the meltwater from which the SPCCs precipitated is indistinguishable from that of the debris-rich BIC basal ice (δ18O –24‰ referenced to Vienna standard mean ocean water), but distinct from that of the overlying white Pleistocene ice (δ18O ∼–35‰), demonstrating that SPCCs are reliable archives of the isotopic composition of only the basal ice of past ice sheets. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.