ABSTRACT: Preliminary account of the glacial history of Bathurst Island, Arctic Archipelago

CGRG Bibliography of Canadian Geomorphology
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Abstract

Bathurst Island, in the central part of the Arctic Archipelago, lacks the prominent glacial landforms such as drumlins and eskers that characterize certain more southerly islands. it does not appear to have been overridden by the continental North American (Laurentide) ice sheet during the last glaciation (classical Wisconsin). Nonetheless Bathurst Island bears undoubted evidence of glaciation in the form of till, erratics, and meltwater channels. Erratics, commonly of a quartzose sandstone that outcrops on the island, are widespread and occur at altitudes up to at least 1,100 feet (335 m), far above the limit of marine submergence. Other important features indicating glaciation are: striae, lakes in bedrock basins, areas of streamlined drift, end moraines, and areas of dead-ice topography. Apparently most of these features are related to locally-centred ice cap(s), but the occurrence of till containing shells above the marine limit at several localities along the east coast may possibly be the result of a glacier tongue in the straits havlng impinged upon the island. The rapid uplift that has taken place in postglacial time, as determined by radiocarbon dating of marine shells from the raised beaches, is believed to have resulted from glacial rebound. Thus the last glaciation of Bathurst Island is inferred to have taken place during Wisconsin time. The altitude of the marine limit is close to 300 feet (90 m) along the east central and southeast coasts, but it reaches 400 feet (120 m) in the long inlets that indent the north coast, suggesting that the ice may have been thicker inthe latter area. The radiocarbon dates on marine shells, plus one on peat, also indicate that much of the island was ice-free by 9,000 years ago. Since then peat deposits have formed in many localities, but in two places buried peats are more than 35,000 years old, suggesting that they are interglacial, or possibly interstadial, in age.

Bibliography of Canadian Geomorphology