History of Quaternary Ice Sheets on Arctic Islands, Phase 1: Integrated Approach Using Dating of Terrestrial Glacial Deposits, Glacially Abraded Bedrock and Marine Shorelines

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The extent of arctic ice sheets during the last glaciation is among the most controversial issues in arctic glacial geology, paleoglaciology and paleoclimatology. One of the main reasons is our inability to accurately date terrestrial deposits that define ancient ice margins. The in situ accumulation of cosmogenic nuclides can be used to approach this problem. In this study, cosmogenic surface exposure dating methods will be used to reconstruct the history of the last arctic ice sheets. The main goals of the proposed integrated study are to provide clear evidence either for or against the existence of the Innuitian Ice Sheet in the late Quaternary, to reconstruct the history of the last ice sheets, from their birth until today, and to determine the duration of ice-free period before the last glaciation started. The investigation will obtain cosmogenic surface exposure ages for glacial deposits and polished bedrock in northwestern Greenland, eastern Ellesmere Island and several small islands between them, western Ellesmere and eastern Axel Heiberg islands, Devon, Baffin, Cornwallis, Somerset, Bathurst, Prince Patrick and Ellef Ringness islands. They will also obtain cosmogenic and radiocarbon ages for raised marine shorelines in order to reconstruct the history of sea level changes at these locations. The results will provide the much needed chronologic control for the late Quaternary glaciations in arctic islands. The results will also have important implications for paleoclimatologic studies because of a possibility to establish whether or not there was a connection between the Arctic Ocean and Baffin Bay during the last glaciation.