Discovery of essential parallelism among the Algonquin and lower Algonquin water-planes of Georgian Bay necessitates considerable revision in later Great Lakes history. The lakes would seem to have drained northeastward to the St. Lawrence–Ottawa sea during the several lower Algonquin stages, and long before the Nipissing channel (North Bay-Mattawa) was used.1 The total number of the stages and the positions of the corresponding outlets are not known, but the lower Algonquin beaches are numerous and cover a wide range of elevation in the north. Investigation of these far-reaching beaches, about Georgian Bay, northern Lake Huron and Lake Superior, combines naturally with the tracing north and west of the four lower Algonquin water-planes already established in southeastern Georgian Bay (Fig. 1). The Cape Rich studies furnish one step toward the solution of this extensive problem.
Field work was done mostly in September, 1936, with the aid of a grant . . .