Field Evidence for Wet-Based Ice Sheet Erosion from the South-Central Queen Elizabeth Islands, Northwest Territories, Canada

Abstract

Glacial erosional features were studied in detail at three locations in the southcentral Queen Elizabeth Islands, Canada. Numerous striated bedrock outcrops, indicating ice flowing from the sea onto the coast, were discovered on BaillieHamilton Island, off the west coast of northern Devon Island. The consistency of obtained ice-flow directions indicates that thick, wet-based ice overrode the >200m-high island from northwest, west-northwest, and northeast, without topographic deflection. We conclude that this ice also flowed across the >300 m deep Queens and Wellington channels bordering Baillie-Hamilton Island. A similar conclusion was derived from striated bedrock outcrops on the northeast coast of North Kent Island, positioned between Devon and Ellesmere islands. Ice flowing from the northwest obliquely across Baillie-Hamilton and North Kent Islands, and from the northeast across Baillie-Hamilton Island, could not have emanated from local ice domes. Instead, these results are consistent with a large ice sheet covering the central and southern Queen Elizabeth Islands with an ice spreading center in the Norwegian Bay region. The timing of these events remains uncertain, but the degree of weathering of the striated outcrops indicates that both northwest and northeast ice-flow directions could be of late Wisconsinan age.