WELLS OF PEORIA COUNTY, ILLINOIS. 673 



PEORIA COUNTY. 

 GENERAL STATEMENT. 



Peoria County is situated on the west side of the Illinois River, imme- 

 diately south of Stark and western Marshall, and opposite Woodford and 

 Tazewell counties. It has an area of 615 square miles, and Peoria is the 

 county seat. The principal stream crossing the county is Kickapoo Creek, 

 which has two forks, one of which drains the northern and the other the 

 western portion of the county. The stream enters the Illinois just below 

 the city of Peoria. The other direct tributaries of the Illinois are very 

 small. Spoon River crosses the extreme northwest corner of the county in 

 a westward course and flows through Knox and Fulton counties before 

 joining* the Illinois River. 



The northeastern part of the county is occupied by two bulky morainic 

 systems, the Shelbyville and Bloonhngton. West from these moraines the 

 uplands are generally plane and stand about 100 feet lower than the main 

 crests of the morainic systems. Like the neighboring portion of Stark 

 County, this plane is covered with loess to a depth of 12 to 15 feet. The 

 morainic ridges to the east are in places nearly destitute of loess, so that 

 surface bowlders are a conspicuous feature. There are other portions of 

 the moraines, however, which carry a deposit of loess-like silt 5 or 6 feet in 

 depth. The sheet of loess which covers the plain west of the moraines 

 passes under them, as indicated on a previous page (p. 187). The thick- 

 ness of the drift in Peoria County is similar to that of Stark, except that 

 the Illinois Valley and the moraine in the northeastern part of the county 

 each have a very heavy drift deposit, 150 to 200 feet or more in thickness. 



The drift usually contains a sufficient amount of sand and gravel at 

 moderate depths to afford water for wells, and in places the entire drift 

 section appears to be composed of sand and gravel. The majority of 

 exposures along Kickapoo Creek are largely of this material, there being 

 but a small amount of till exposed. In the morainic ridges in the northeast 

 part of the county much till is usually found in wells. Excellent exposures 

 of the till are to be seen along the Santa Fe Railroad in its descent to the 

 Illinois Valley between Edelstein and Chillicothe. 

 • mon xxxviii 43 



