GLACIAL LAKES TAYLOR. 299 



early beginnings of the larger lakes became well established. There 

 is some evidence of this sort of development at Fort Wayne, Ind. 



The earliest small lakes discharged at first southward independently 

 through several gaps in the divide; a little later they fell to lower 

 levels and discharged westward to a lower gap, and finally into the 

 first small, narrow representative of glacial Lake Maumee. Mr. 

 Leverett has already described these earliest lakes in Ohio.^ Others 

 of somewhat similar origin were formed along the east side of the Lake 

 Micliigan basin. Winchell - has described a series of small lakes that 

 preceded the larger lakes in the western end of the Lake Superior 

 basin. 



So far as has been made out by the study of (he moraines, espe- 

 cially with reference to their continuity from one basin to another, 

 there seems to have been very little difference in the time when the 

 larger lakes began to form in the western end of the Lake Erie and 

 the southern end of the I^ake Michigan basins. When the ice front 

 had withdrawn to a position a few miles north of the watershed at 

 the south end of I^ake Michigan and was building the later members 

 of the lake-border group of moraines, there was a long, slender, cres- 

 cent-shaped lake between the ice and the land. This was the begin- 

 ning or first stage of the glacial Lake Cliicago (fig. 2, position M). 

 Similarly, when the ice front had retreated to a position a little east 

 of tlie watershed at Fort Wayne, Ind., another long, narrow, crescent- 

 shaped lake, called glacial Lake Maumee, was formed between the 

 ice and the land. If the moraines have been rightly interpreted, 

 these two lakes came into existence at about the same time. A third 

 lake of the same land was formed in the same way at the western end 

 of the Lake Superior basin, when the Lake Superior ice lobe first 

 shrank within the line of the watershed west of Duluth. The time 

 of its first appearance relative to the first lakes formed at Chicago and 

 Fort Wayne is shown by Leverett's work in 1910 to be considerably 

 later. 



Two small lakes, formed probably at about the same time as Lakes 

 Maumee and Chicago, gathered in front of the Green Bay lobe of the 

 ice sheet in Wisconsin and discharged, the one southward to Rock 

 River and the other southwestward to the Wisconsin River. These 

 lakes, however, did not have an independent existence long. They 

 soon united in one ])ody and when the retreating ice opened a 

 ])assage eastward to the basin of Lake Michigan, merged with Lake 

 Chicago. 



From these four relatively small beginnings there grew a series of 

 glacial lakes the like of which, for size and complicated liistory, is 



1 Leverett, Frank, Glacial formatiooa and drainage features of the Erie and Ohio basins, Mono. U. S. 

 Geol. Survey, vol. 41, 1902, pp. GIO-GII. 

 " Winchell, N. U., Glacial lakes of Minnesota: Geol. Soc. .\m. Bull., vol. V2, 1901, pp. 10*-128, 1 pl. 



