Northernmost (?) Glacial Lake Algonquin Series Shorelines,Sudbury Basin,Ontario

Shorelines of Lake Algonquin, the largest of the glacial lakes of the Great Lakes area, are well known in southern Ontario, but are sporadic and difficult to trace northward onto the Precambrian shield. Improved knowledge of the extent and uplift pattern for Algonquin shorelines is needed to support geophysical models of isostatic response, interpretation of glacial and glacial lake history, and the search by archeologists for evidence of Paleoindian activity, shown to be localized along its shoreline. The Sudbury basin is one of the few areas of mapping of Quaternary geology on the Canadian shield that provides a record of Algonquin lake phases. Meltwaters from the northward-receding ice front formed a series of deltas southward into the Sudbury basin in central Ontario around the time the Cartier I moraine was deposited. Instrumental surveys of deltas, bars, and shorebluffs carried out in the northern Sudbury basin delineate several discrete water planes. Correlation with previously surveyed and correlated shorelines on Manitoulin Island, southwest of Sudbury, indicates the presence of an upper Algonquin shoreline and features correlated to the Cedar Point, Payette, Sheguiandah, and Korah levels. Features southwest of the Sudbury basin at Nairn correlate with Korah and post-Korah water levels. Land between Nairn and Sudbury is too elevated to have been reached by the later Nipissing transgression. Similar shoreline sequences have been surveyed near North Bay, with results supporting the findings of this study.