CGRG Bibliography of Canadian Geomorphology
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Author : Dredge, L.A.
Date : 2004.
Title : Late Quaternary history, central Baffin Island.
Publication : 49th Annual Meeting of the Geological Association and the Mineralogical Association of Canada. May 12-14, 2004. Brock University, St. Catharines, Ontario.
Issue :
Page(s) :
Abstract
Early field work, recent cosmogenic dates and ice-mass models have suggested a major flow of glacier ice across Baffin Island from Foxe Basin before and during the last glacial maximum (LGM). An ice stream carried carbonate drift across the peninsula from Wordie Bay to Ekalugad Fiord across relatively low terrain, but limestone indicators relating to Foxe Ice do not extend far inland in other areas. It is possible that Foxe ice was cold-based for most of the LGM. Striations, indicator erratics, and landforms suggest later glacial flow from a Baffin ice centre. The prevalence of weathered rock, lack of ice-scoured lake basins, and absence of striations on the central plateau suggests that the island spine was a major ice divide, and that ice flowed out towards the two coasts. Baffin Ice may have been cold-based much of the time, producing rubble fields. Sharply defined swaths of eroded bedrock indicate that Baffin–centred ice was warm-based at some places and at some times, but cold-based at others. Crossing striations indicate that the ice-flow centre gradually shifted northwestwards towards the present Barnes Ice Cap, and that ice tongues located in valleys flowed towards both coasts during ice recession. Deglaciation began more than 9200 years ago in the eastern outer fiords. Massive upland end moraines developed along the eastern part of the field area, crossing the heads of fiords about 8000 years ago when sea level was about 50-60 m above present. The Foxe Basin coast became ice-free about 6700 years ago when sea level stood at 110 m. Other large end moraines on the plateau, ice-dammed glacial lakes with sublacustrine moraines, and stacked sets of meltwater channels trace the pattern of ice recession towards and along the central plateau, and the recession of ice tongues from major valleys towards the Barnes Ice Cap. Lichen-free zones on the east side of the field area and around the west side of the Barnes Ice Cap denote areas of snow and icefields during the Little Ice Age. Recent photography shows that there has been substantial ice recession on the western side of the Barnes Ice cap, but a stabilized front or advancing ice on the eastern side. Changes in ice-sheet profile are due in part to surges into proglacial lakes. Highland ice caps are generally receding.
Bibliography of Canadian Geomorphology