612 THE ILLINOIS GLACIAL LOBE. 



feet, but a much stronger supply was struck at about 1,200 feet. The drift 

 is largely gravel and has a depth of 61 feet The well is situated in a 

 valley about 100 feet below the bordering uplands, and rock appeal's in the 

 uplands near by at a level fully 50 feet above the well mouth. A well at 

 the railway station in Mount Carroll reaches rock at a depth of 60 feet. 

 The altitude there is 816 feet above tide. This well penetrated a complex 

 series of beds of gravel, sand, and till. A boring at William Petty's, 4 

 miles southwest of Mount Carroll, is reported to have penetrated about 300 

 feet of drift. On the farm of R. Hostetter, 3 miles southeast of Mount 

 Can-oil, a well strikes rock at the depth of 72 feet; the drift is mainly a 

 blue clay. Hon. James Shaw reports a well section near Mount Carroll, 

 which struck a black mucky clay, apparently a soil, at a depth of about 50 

 feet; another well at the farm of F. O'Neal, 3 miles from Mount Carroll, 

 passed through a soil and wood at 15 to 20 feet. The latter is perhaps at 

 the junction of the loess with the underlying glacial drift, but the former 

 penetrated a sheet of glacial drift above the soil, and its section is as 

 follows : 1 



Section of a well near Mount Carroll, Illinois. 



Feet, 



Soil, yellow and blue clays 15 



Reddish clay and gravel 15 



Tough blue clay 2 



Coarse gravel 3 



Yellow sand 11 



Black mucky clay - 5 



A deep artesian well has been sunk in a creek valley about 4 miles 

 south of Mount Carroll, which overflows with considerable force. No 

 further data have been obtained. 



At Lanark the public water supply is from a well obtained near the 

 top of the limestone at about 100 feet. The following drift beds were 

 penetrated: Clay, 12 or 15 feet; gravel and sand, 12 or 15 feet; blue clay, 

 with few pebbles, 75 feet. A well at L. Sprecher's, 1 mile west of Lanark, 

 enters rock at about 100 feet and there obtains water. In the township 

 east of Lanark wells are reported to differ greatly within short distances in 

 the amount of drift penetrated, some entering- rock at about 20 feet while 

 others penetrate 100 feet or more of drift. 



1 Geology of Illinois, Vol. V, p. 80. 





