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MORRIS M. LEIGHTON 



southern Illinois outside of the Bloomington, the writer prefers to 

 correlate the Belvidere lobe with one of these, more plausibly the 

 Champaign drift, inasmuch as the two are more nearly equivalent 

 in the strength of their marginal expression and in the feebleness of 

 their outwash deposits. 



Fig. 3. — Graphs showing the number of borings recording a certain depth of 

 leaching in the Belvidere, Bloomington, and lULnoian drift areas. 



The source of the drift. — The question has been raised by Mr. 

 Leverett, of the United States Geological Survey, as to whether or 

 not the drift in the vicinity of Belvidere was deposited by a Green 

 Bay lobe or by a protrusion of the Lake Michigan lobe. The pres- 

 ence of short morainic ridges south of the Kishwaukee River which 

 trend northwest-southeast, offers some support to the former idea, 



