8S2 



GEOLOGY 



Fig. 586. A later stage in the development of Lakes Chicago, Maurne 

 and Saginaw. (Leverett and Taylor, U. S. Geol. Surv.) 



Fig. 587. Illustrating the relations of standing water to the ice in the 1 -'.i -it- 

 alic! Ontario regions after the ice had retreated farther than repre- 

 sented in Fig. 586. The numerous lobate lakes south of the Ontario 

 lobe of ice will be noted, and also the fact that the discharge of Lake 

 Warren was still to Lake Chicago. (Taylor and Leverett, U. S. (ieol. 

 Surv.) 



shifted to its present position, probably by a gentle upwarpinir 

 of the surface at the north. 1 



Similar complicated histories doubtless attended the retreat 



1 An account of the history of the Great Lakes, by I 1 ', li. Taylor, i- found 

 in Studies in Indiana Geography. See also (Joldthwaitc, Bull. XVII, \\ i 

 sin Surv., and Bull. VII, Geol. Surv. of 111. 



