402 THE ILLINOIS GLACIAL LOBE. 



A well in sec. 6, on the inner slope of Covert Ridge, has the following 



section: 



Section of well on Covert Ridge in sec. 6, T. 1 N., R. 17 W. 



Feet. 



Surface sand 12 



Blue clay, slightly pebbly 10 



Fiue white saud with a few pebbles 32 



Cemented gravel alternating with beds of loose gravel 24 



Total 78 



Iri sec. 12, T. 1, R. 17, also on the inner slope of Covert Ridge, wells 

 30 to 50 feet in depth are mainly through sand, and the lake border from 

 this point northward is heavily coated with sand. 



On the outer slope of Covert Ridge, in northern Casco Township, till 

 appears to have been deposited upon a thick bed of sand. The wells enter 

 this sand at a depth of 10 to 25 feet, and those sunk to a depth of 35 or 40 

 feet do not reach the bottom. 



On a swamp south of Covert Ridge, in southeastern Ganges Township, 

 wells usually pass through a compact clay after leaving the surface muck, 

 and find some difficulty in obtaining water in dry seasons. A well in sec. 

 36 reached a depth of 98 feet and found only a weak vein at about 40 feet. 



A well on the crest of Covert Ridge, in sec. 16, Ganges Township, at 

 an altitude about 100 feet above the lake, reached a depth of 275 feet with- 

 out entering rock. Its section is as follows: 



Section of well on Covert Ridge, in Canges Township, Allegan County, Michigan. 



Feet. 



Surface sand 6 



Blue till <55 



Blue quicksand - - H 



Yellow sandy clay with pebbly layers 150 



Blue till « 20 



Yellow sandy clay, changing to saud at bottom 30 



A well in the northwest part of sec. 15, also on the crest of Covert 

 Ridge, penetrated 30 feet of surface sand, beneath which was a blue till 

 extending to the water-bearing sand at 86 feet, 



A well on the crest of the ridge, near the line of sees. 3 and 4, at an 

 altitude 105 feet above the lake, reached a depth of 190 feet without enter- 

 in^ rock. There is 8 feet of yellow till at the surface, beneath which the 

 well appears to have been entirely in a blue-gray till. 



In the vieinitv of Hutchinson's Lake the wells range in depth from 40 

 to 105 feet and are largelv through sand or sandy gravel. 



