GLACIAL AND GLACIOLACUSTRINE EVENTS IN NORTHWESTERN LAKE HURON, MICHIGAN AND ONTARIO.

Data on ice flow direction compiled from the literature reveal two glacial flow directions in northwestern Lake Huron. A succession of glacial and postglacial lake levels affected the area. Plane table profiles show that on St. Joseph Island, most of the Algonquin succession can be identified by correlation with published data from Sault Ste. Marie and Manitoulin Island. Deglaciation of the region occurred between the Onaway Advance (11,800 yr B. P. ) and the Marquette Advance (10,000 yr B. P. ). Ice retreat took place as Lake Algonquin spread northward, leaving a series of shorelines during isostatic uplift and opening of the sequence of outlets near North Bay, Ontario.