MICHIGAN ACADEMY OF SCIENCE. 



33 



part of the Thumb, Lake ^^'hittle,sey abandoned the Ubly Outlet, and 

 the waters in the Huron-Erie basin became confluent Avith those in the 

 Saginaw. The lake extended so far outside the limits of the Saginaw 

 basin that it has seemed inappropriate to call it Lake Saginaw, and 

 the name Lake \\'arren has been applied. Its eastern end was in the 



Fig. 5. Lake Whittlese}', with correlative ice border. 



Finger Lake region of central Xew York, and it covered a large area 

 on all sides of Lake Erie (Fig. G). During its existence the ice was still 

 present in the Ontario basin and prevented eastward discharge. The 

 outlet was westward through Grand River to Lake Chicago. Th!e 

 Avater level was sufficiently high to submerge the site of Niagara Falls to 

 a depth of about 2o0 feet. 



Fig. 6. Lake AA'arren, with probable correlative ice border. 



