WELLS. OF LEE COUNTY, ILLINOIS. 609 



INDIVIDUAL AVELLS. 



At Dixon the public water supply is obtained from three artesian wells, 

 1,637, 1,710, and 1,810 feet in depth, which terminate in the Potsdam 

 sandstone. The wells overflow into a reservoir, from which the water is 

 pumped to a standpipe. An analysis of the water, published in the Seven- 

 teenth Annual Report of this Survey, 1 shows a very small amount of salt 

 and a moderate degree of hardness. The water is considered of pleasant 

 taste and excellent quality. The wells are cased only about 50 feet. The 

 water in each well has a temperature 55° F. 



At Nachusa wells are usually obtained at about 30 feet without entering 

 rock. A well one mile northwest of the village reached a depth of 95 feet 

 without striking rock. Within a half mile of this well, however, rock 

 outcrops at a higher elevation than the well mouth. 



At Franklin Grove, and also at Ashton, wells usually enter rock at 30 or 

 40 feet, and there are numerous outcrops of rock in that vicinity. In several 

 instances coal has been found in the drift in the vicinity of Ashton. As this point 

 is north of the border of the coal field, it suggests a northwestward movement 

 of the ice in this region, though the occurrence of coal here may perhaps be 

 due to the presence of outliers north of the main coal field. As indicated 

 below, coal apparently underlies the southeast corner of this county. 



The drift is thin over the southern half of T. 39, R. 1 E., and northern 

 half of T. 38, R. 1 E., but north and east from this locality wells occasion- 

 ally reach depths of 50 and even 100 feet without entering rock. The 

 deepest section of such a well, noted in T. 39, is that of Robert Peile, in 

 sec. 23, which reached a depth of 108 feet. The well has the following 



section : 



Section of Peile well in T. 39, B. 1 E. 



Feet. 



Soil and brown till 10 



Gravel 1 



Blue till 20 



Gravel 5 



Brownish till, with occasional gravelly beds 72 



The upper 36 feet of this section should perhaps be referred to the 

 Iowan stage of glaciation. Blue till is occasionally entered in that vicinity 

 at only 6 or 7 feet below the surface, or at a much shallower depth than in 

 the drift of the Illinoian stage. 



1 Part II, p. 827. 

 MON XXXVIII 39 



