Reconnaissance Surficial Geology, Hill Island Lake, Northwest Territories, NTS 75-C.

Résumé du livre

Reconnaissance mapping, through air photograph interpretation and limited legacy field data in the Hill Island Lake map area, provides a basic understanding of surficial sediments and glacial history. Bedrock is well exposed throughout the map area but more extensive in the northern half. Till blanket, veneer and glaciofluvial outwash become increasingly more abundant towards the southern third of the map area. Drumlinized till, crag-and-tails, and striations record ice advance to the southwest. Small isolated moraine ridges may reflect deglacial stagnant ice. Glaciofluvial corridors of eskers and scoured bedrock, record a southwestward meltwater flow during deglaciation. Some corridors are topographically controlled. In the Hill Island and Taylor Lake basins, glaciolacustrine deltas are found at 340 m. Pockets of glaciolacustrine sediments occur along the Thoa, Nolan, Abitariver basins, and in the Oswald, Delight, Kidder and other smaller lake basins. These are interpreted to be short lived, ice-dammed glacial lakes. Postglacial dune ridges up to 1-2 km long trend NW-SE.