212 THE ILLINOIS GLACIAL LOBE. 



rivers, and also farther north and south, which, as above noted, seems to 

 have been derived from the Shelbyville drift rather than brought by wind 

 from the plain of lowan loess on the west. 



On Farm Creek, which enters the Illinois River opposite Peoria, and on 

 small western tributaries of the Illinois just north of Peoria, as well as 

 on the borders of the Illinois Valley in the vicinity of that city, there are 

 gravel deposits which it is thought are derived in the main from the Bloorn- 

 ington moraine, though some of the deposits west of the river may prove 

 to be connected with the Shelbyville. Those along Farm Creek may be 

 traced with but slight interruption eastward into connection with the Blooni- 

 ington moraine. These gravel deposits have a remarkably high altitude 

 above the Illinois Valley, their elevation being about 175 feet above that 

 stream on each side of the Illinois Valley at Peoria. It would seem, there- 

 fore, that the Illinois and its tributaries have been cut down this great 

 amount at the point where the Shelbyville moraine crosses the river, since 

 the Shelbyville stage, and probably since the Bloomington. However, the 

 valley was apparently rilled here to a greater height than at points above 

 and below. A view of the gravel at Peoria is given in PL XIII. It is of 

 medium coarseness, and in this respect harmonizes with that usually found 

 in terraces that head in the Bloomington morainic system. It is coarser 

 than is commonly displayed by the terraces that head in the Shelbyville 

 drift sheet. 



Kickapoo Creek and its tributaries, which lead away from the Shelby- 

 ville moraine in northern Peoria County, have terraces of sandy gravel 

 which are doubtfully referred to the Shelbyville stage. They may prove 

 to be simply incidents in the cutting down of the valleys through the some- 

 what sandy drift deposits outside the Shelbyville moraine. There appears 

 to be no gravel ten-ace along Kickapoo Creek that can be correlated with 

 the Bloomington moraine, though the stream heads in that moraine. 



In view of the evidence just cited concerning the character of the out- 

 wash, it appears that in general it was weak, and it is doubtful if a vigorous 

 outwash at any point can be proved. 



