Coalescent Greenland and Innuitian ice during the Last Glacial Maximum: revising the Quaternary of the Canadian High Arctic

摘要: Abstract This paper constitutes a fundamental revision of the author’s earlier research and resolves long-standing debate concerning late Quaternary history Canadian High Arctic, supporting its inundation by glaciers during Last Glacial Maximum (LGM). A transect along east Ellesmere Island demonstrates that ice advanced northward southward axis Nares Strait Wisconsinan, debouching from central saddle in Kane Basin. The configuration Greenland is based on moraines, meltwater channels erratics. youngest AMS 14C date obtained shelly till suggests buildup after 19 ka BP whereas many other dates are younger than 30 ka BP. Furthermore, lowest (youngest) detectable amino acid ratios shells postdate Robeson aminozone (>70 ka BP) separated Holocene narrow gap wholly consistent with occupation strait Wisconsinan ice. Re-entry sea throughout shown series paleogeographic maps geomorphic evidence radiocarbon associated marine limit. Deglaciation at north end occurred 10.1 ka BP and, south end, 9.0 ka BP. may still have been blocked Basin 8 ka BP, however; 7.5 ka BP it provided an unobstructed seaway Arctic Ocean to Baffin Bay. prominent margins within fiords eastern Island, previously considered mark last limit, record regional stabilization land-based breakup preceding marine-based margins. Other implications this study are: post-30 ka BP (and possibly post-19 ka interval widely assumed be constrained severe aridity high arctic; coalescent LGM promoted thickening divide, causing enhanced westward flow across island Eureka Sound. Sizeable postglacial emergence (80–120 m) retreat thick (⩾1 km) strait. Greater Sound, which extends into arctic islands, confirms proposed Innuitian Ice Sheet. Further clarification extent, geometry, Sheet will provide new opportunities for glaciological geophysical modelling, help identify sediment sources