ABSTRACT: Glacial and sea level history, Western Fosheim Peninsula, Ellesmere Island, High Arctic Canada

CGRG Bibliography of Canadian Geomorphology
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Abstract

Discontinuous moraines and meltwater channels that either encircle broad uplands or occupy the lower valleys of cirque basins record a restricted ice cover on western Fosheim Peninsula at the last glacial maximum. During deglaciation (8200-9600 BP), meltwater reached the sea, depositing thick sequences of glaciomarine sediments. High sedimentation rates were sustained through the early Holocene warm period, demonstrating the importance of precipitation for the maintenance of high arctic glaciers. Beyond the last ice limit, there is abundant evidence of older, more extensive glaciations. The oldest recorded advance inundated Fosheim Peninsula and was likely responsible for the deposition of erratics on the highest summits. Fossiliferous till contains shells that have similar amino acid ratios to the Kap Kobenhavn Formation, northern Greenland, dated 2.4-3.2 Ma and to till deposited by the maximum advance of the Greenland Ice Sheet onto northeastern Ellesmere Island. This glaciation may be as old as 2.4 Ma. During a subsequent glaciation, regional ice sources coalesced on western Fosheim Peninsula. Moraines, meltwater channels and outwash record ice retreat in conjunction with higher relative sea levels between 170 and 185 m asl. The maximum age of this glaciation is estimated to be ca. 2 Ma; however, it may be as young as 0.4-0.7 Ma based on paleoclimatic considerations. Because precipitation is regarded as the critical climate control on modern glacier growth, it has been argued that more extensive glaciations were favoured by much greater precipitation and a marked reduction in the Arctic Ocean sea-ice cover. This relationship appears consistent with the geological evidence for older glaciations on western Fosheim Peninsula.

Bibliography of Canadian Geomorphology