114 LIFE OF THE PLEISTOCENE 



represents the advances and retreats of the ice sheet. This condition may be 

 expressed as follows: 



Lakes of Huron-Erie-Ontario Basin 



1. Lake Maumee. First stage, Fort Wayne- Wabash outlet. 



Second stage, Imlay-Chicago-Grand outlet. 

 Third stage, Ubly-Chicago-Grand outlet. 



2. Lake Arkona. Chicago-Grand outlet. 



3. Lake Whittlesey. Chicago-Grand outlet. 



4. Lake Wayne. SyTacuse-Mohawk outlet. 



5. Lake Warren. Chicago-Grand outlet. 



6. Lake Lundy. Syracuse-Mohawk outlet. 



6. Lake Erie 



The ice eventually shrank within the Ontario basin and the discharge was 

 shifted to a low coll at Rome, New York. This lowered the waters about 150 

 feet below the crest of Niagara Falls and the cataract came into action. The 

 waters of the Erie basin were drawn down to the level of the Niagara River 

 outlet. The first Lake Erie beach lies within the present Lake Erie and it is 

 believed that this lake began as a small body of water in the eastern end and 

 gradually filled the basin to the west. Submerged lower courses of streams 

 in the west end of the basin present conclusive evidence of this ancient con- 

 dition. During its postglacial existence, Lake Erie has had two periods of 

 low water, one at the time of the Kirkfield (Trent River) outlet, and the second 

 at the time of the North Bay (Ottawa River) outlet. Both lower beaches 

 are now submerged. 



H. ONTARIO BASIN (LAKE IROQUOIS) 



"When the Lake Ontario ice lobe had retreated far enough to uncover the 

 southern parts of the valleys of the Finger Lakes in central New York, small 

 lakes gathered in them, at first as separate bodies. With continued: recession 

 these lakes were lowered and combined in a complex series of changes leading 

 finally to the later, large lakes that filled the whole basin of Lake Ontario. 

 The first local glacial lakes had independent outlets toward the south" 

 (Taylor). 



The dozen or more small lakes in the Finger Lake valleys finally merged 

 into one lake, Lake Newberry, with an outlet southward from Seneca Lake to 

 the Susquehanna River. 6 Later, Lake Hall followed with an outlet westward 

 to the Lake Erie basin. Lake Van Uxum followed, with an outlet eastward 

 to the Mohawk Valley. Next came Lake Dawson, when the waters fell below 

 the level of Lake Erie, and the outlet was eastward past Syracuse. Finally, 

 Lake Iroquois was formed, when the waters of the Ontario basin fell to the 

 level of the pass at Rome, N. Y., and discharged eastward thru the Mohawk 

 Valley into the Hudson River and thence to the Atlantic Ocean (Plate LII). 



6 See Fairchild, Bull. N. Y. State Museum, No. 127. 



