The first stage occupied only the south part of the basin of Lake Huron, including Saginaw Bay. It received tributary drainage from smaller lakes in the south part of the Georgian Bay and Lake Simcoe basins. Its existence is based on evidence of the establishment and erosion of its outlet through the distributaries of the St. Clair River at St. Clair, and on characters of the Niagara River and gorge. The steps of transition following this are simply physical and logical necessities, made so by the conditions of development from the first stage to the later fully developed Lake Algonquin, which included all three of the upper Great Lake basins. • Kirkfield Low Stage • Lake Chicago-Huron Stage • Main Lake Algonquin, 11,000 YBP, the main phase of Lake Algonquin formed across both the
Lake Michigan and
Lake Huron basins, then overflowing the low lands of Michigan's
Upper Peninsula. Water levels continued to fluctuate. Four water tables existed long enough to form identifiable beaches. They include the Main Algonquin, Lower Algonquin, Battlefield and the Fort Brady beach levels. By 10,500 YBP the lake gained a lower outlet across the front of the glacier, creating the
North Bay Outlet. Running in reverse to the modern
French River, and across the divide into the ancestral
Ottawa River. With water levels dropping, the two basins of Michigan and Huron, separated into individual lakes, entering the
Lake Chippewa low phase in the Michigan Basin and the
Lake Stanley Low Phase in the Huron Basin.
Early Lake Algonquin The Early Lake Algonquin covered only part of Lake Huron. It included Saginaw Bay, but did not include
Georgian Bay or any of the Lake Michigan or Lake Superior basins.
Lake Chicago was in the southern portion of
Lake Michigan and
Lake Duluth was in the western tip of the
Lake Superior basin. Lake water drained through the
Port Huron outlet and down the
St. Clair and
Detroit rivers into Early Lake Erie. As the glacial front melted northward, the lake expanded in the Huron basin. When it retreated north of
Alpena, Michigan, the waters of Lake Chicago merged with Early Lake Algonquin. The two lakes were nearly the same level and no change of altitude. Each maintained its original outlets; the Port Huron outlet on the southeast and the Chicago outlet in the southwest. ==See also==