176 A. p. COLEMAN LAKE IROQUOIS AT TORONTO 



lake Ontario. What absolute higlits the}^ had above the sea one can 

 hardly guess in the case of the first four, and even as regards lakes War- 

 ren and Iroquois the elevation above sealevel must for the present remain 

 very doubtful. 



It has seemed unwise to give separate names to the old lakes whose 

 deposits lie, as one might say, encapsuled within one another in the 

 Ontario basin, and reference has been made only to the various stages 

 clearly shown in the drift of the region. The Iroquois beach, so mag- 

 nificently displayed and so thoroughly studied, deserves, of course, a dis- 

 tinctive name. Possibly the example set by Tyrrell in his account of the 

 old beaches west of Hudson bay might be followed })rofitably, naming the 

 ancient lakes Epi-ontario number 1, number 2, etcetera. This method 

 seems most applicable, however, to instances where there are well-de- 

 fined beaches. When the dam at the outlet rises steadily without dis- 

 tinct pauses, as seems to have occurred when the Don interglacial stage 

 merged into the Scarboro interglacial stage near Toronto, it is clear that 

 no sharp line should be drawn between the successive bodies of water. 



The complicated bit of history outlined in this paper affords fresh proof 

 of the delicate balance of affairs in the Great Lakes region during the 

 last few tens of thousands or hundreds of thousands of years, and is sug- 

 gestive of the kind of changes which it may undergo in the future. Is 

 the rest of America and the world in a condition of unstable equilibrium 

 like that of the region of the Gi'eat lakes ; or are the Great lakes situated 

 where they are because the region is subject to greater and more frequent 

 changes of level and of attitude than others ? 



