GEOLOGY OF THE TORONTO REGION
The shore deposits of Lake Iroquois at Hamilton and Toronto have a thickness of more than one hundred feet, and in the gravel bars remains of mammoth, caribou and other mammals, as well as fresh-water shells, have been found. As the lake had one shore of ice the water must have been cooler, and probably the climate also, than that of the present Ontario valley.
Lake Algonquin, as worked out by Spencer, Taylor, Goldthwaite and others, was probably the greatest of the glacial lakes, including the basins of Lake Superior, Lake Nipigon, Lake Michigan, Lake Huron and Georgian Bay, and a large amount of the lowlands adjacent. Its outlet appears to have been first by Niagara River over Niagara Falls into Lake Iroquois, but later by the Trent Valley. Its beaches occur near London, Barrie and other points west and north of Toronto. They are even more strongly developed than those of Lake Iroquois, since the lake was larger and perhaps somewhat longer lived than the one in the Ontario basin.
The history of Niagara Falls begins with the outflow of the Algonquin waters through the Erie valley and then northward over the Niagara escarpment into the basin of Lake Iroquois. The history of the falls has interested geologists ever since the