GEOLOGY OF THE TORONTO REGION 



The shore deposits of Lake Iroquois at Hamilton 

 and Toronto have a thickness of more than one hun- 

 dred feet, and in the gravel bars remains of mam- 

 moth, 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. 



Lake Algonquin, as worked out by Spencer, Tay- 

 lor, Goldthwaite and others, was probably the great- 

 est 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. 



NIAGARA FALLS. 



The history of Niagara Falls begins with the 

 outflow of the Algonquin waters through the Erie 

 valley and then northward over the Niagara escarp- 

 ment into the basin of Lake Iroquois. The history 

 of the falls has interested geologists ever since the 

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