GLACIAL FEATURES OF THE NORTH-CENTRAL LAKE SUPERIOR REGION, ONTARIO

Abstract

The surficial glacial features and glacial events of a 13 000 square mile area in northern Ontario are described, based on field work and study of aerial photographs. Ice-laid and glaciolacustrine materials suggest a complex history of stationary ice fronts and glacial lakes during deglaciation. Lakes in the Lake Nipigon and Lake Superior basins inundated large areas. Post-Minong lake stages in the Superior basin intruded far to the north, dammed by ice at the largest moraine, the Nakina. The northern part of this lake was later separated from the post-Minong lake by differential uplift and was named Lake Nakina. After the withdrawal of the ice, Glacial Lake Barlow–Ojibway occupied the northeastern part of the area, and much of it was later overridden by the last glacial readvance. Stratigraphic correlations with radiocarbon dates suggest that the Nakina moraine was built some 9 400 years ago, and that the last glacier ice disappeared before 6 390 years ago.