Revising the limit of the NW Laurentide Ice Sheet: extensive glaciation in NE Beringia
Laurentide Ice Sheet, ice sheets, Canadian Arctic Archipelago, glaciation
For the past half-century, reconstructions of North American ice cover during the Last Glacial Maximum have shown ice-free land distal to the Laurentide Ice Sheet, primarily on Melville and Banks islands in the western Canadian Arctic Archipelago. Both islands reputedly preserve at the surface multiple Laurentide till sheets, together with associated marine and lacustrine deposits, recording as many as three pre-Late Wisconsinan glaciations. The northwest corner of Banks Island was purportedly never glaciated and is trimmed by the oldest and most extensive glaciation (Banks Glaciation) considered to be of Matuyama age (>780 ka BP). The view that the western Canadian Arctic Archipelago remained largely ice-free during the Late Wisconsinan, serving as the NE extremity of Beringia, is reinforced by a recent report of two woolly mammoth fragments collected on Banks and Melville islands, both dated to ∼22 ka BP. Well developed periglacial features present, in particular on Banks Island, have also been considered to record a long interval of ice-free conditions throughout the LGM.
Presented on May 6, 2010 at the European Geosciences Union General Assembly in Vienna, Austria.
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