wells of Mchenry county, Illinois. 577 



In the vicinity of English Prairie post-office, in the northeast part of 

 the county, there is an extensive gravel plain standing at an elevation 

 slightly above 800 feet, in which occasional wells have been sunk to a depth 

 of 150 feet without reaching rock, mainly through gravel. 



At Woodstock, the county seat, a boring was made some years ago 

 which struck a black soil at about 160 feet, beneath which was till, in which 

 the well terminated at a depth of 180 feet. This soil, like that at Alden, 

 probably marks the junction between the Wisconsin and Iowan drift sheet, 

 or possibly between the Iowan and Illinoian. A well has been sunk in Wood- 

 stock to a depth of 1,014 feet, but no accurate record of the strata penetrated 

 appears to have been kept. The drift has a thickness of 230 feet. The well 

 is said to terminate in sandstone, probably St. Peter. A water-bearing "sand 

 rock" was entered at 825 feet. The water is reported to be soft and of a 

 pleasant taste, and has a capacity of 150 gallons per minute from a pipe 6£ 

 inches in diameter. The head is 60 feet below the surface. Many private 

 wells in Woodstock and vicinity obtain water at depths ranging from 20 to 60 

 feet. They are mainly through till, though beds of sand and gravel occur. 



At Marengo the wells vary greatly in depth, those on the gravel 

 plain along the Kishwaukee being but 20 to 25 feet, while those on the slope 

 of the moraine in the south part of the city are often 60 to 80 feet, and 

 occasionally 125 feet or more. So far as ascertained, no wells reach the 

 rock. The drift is largely of gravelly constitution. A well belonging to 

 Mr. P. T. Parkhurst, 100 feet in depth, penetrated a black muck tit about 

 60 feet, from which inflammable gas issued. This muck probably underlies 

 the Wisconsin drift sheet. A similar muck was struck on the farm of James 

 Smith, 3 miles northwest of Marengo, at a depth of only 28 to 30 feet. The 

 well stands on the slope of the outer moraine of the Wisconsin drift, slightly 

 above the level of the older sheet of drift to the west. The soil in all prob- 

 ability is at the base of the Wisconsin drift and above the Iowan drift, At 

 a cheese factory south of Marengo, in sec. 11, T. 43, R. 5 E., a well struck 

 a black muck beneath blue till at a depth of 70 feet. As the well is 

 situated on the moraine at about 70 feet above the Iowan drift plain to the 

 west, the soil probably caps Iowan drift. 



At the village of Crystal Lake wells usually obtain water at depths of 

 50 to 70 feet and are largely through gravel. A well about 4 miles south- 

 west of this village, in sec. 12, T. 43, R. 7 E., reached a depth of 210 feet 



MON XXXVIII 37 



