688 THE ILLINOIS GLACIAL LOBE. 



presumably Kinderhook; the next 335 feet is probably to be referred to 

 the Niagara and Hudson river formations ; and the next 305 feet to the 

 Galena and Trenton. 



The public water supply for the city of Lewistown is obtained from a 

 series of wells in Spoon River Valley about 20 feet in depth. The town is 

 situated on an upland, probably 130 feet above the river, and the wells 

 there are obtained from gravel in the glacial drift at a depth of 25 to 35 

 feet. 



At Astoria, in the southern part of the county, wells are obtained at 

 20 to 40 feet from sand below till. The drift in that vicinity ranges from 

 30 to 70 feet in depth, and is largely till. 



At Vermont, on the west border of the county, wells are usually 

 obtained at 25 to 35 feet. The drift in the vicinity of that village is about 

 60 feet in depth. A test boring for coal, oil, etc., was made at this village 

 to the depth of 2,487 feet, which probably reached the Potsdam sandstone, 

 but the boring is not utilized for water. 



At Ipava a well 1,570 feet in depth supplies the waterworks, and 

 is used also by a woolen mill. A sulpho-saline water was struck, probably 

 in the Galena, at a depth of 1,010 feet. A water of more pleasant taste is 

 obtained from the St. Peter sandstone. Strong wells are obtained in the 

 vicinity of this village, either from drift or from rock, at about 100 feet. 



MASON COUNTY. 

 GENERAL STATEMENT. 



Mason County is situated on the east side of the Illinois River opposite 

 Fulton County, and has an area of 560 square miles, with Havana as the 

 county seat. The county occupies a low basin-like expansion of the Illinois 

 Valley, heavily covered with sand, except where old river channels have left 

 a surface deposit of muck. The drainage is imperfect, and extensive arti- 

 ficial ditching has been necessary to render the old river channels produc- 

 tive. Much of the county is so sandy that it is not cultivated. The eastern 

 portion, however, is very fertile, the sand there being a fine deposit approxi- 

 mating a loess. 



The thickness of the drift is known only at a single point — Mason — 

 where it is 204 feet. The wells are usually obtained at depths of 20 to 40 

 feet, but at Havana they are frequently sunk to a depth of 70 feet, through 

 sand and gravel. 



