216 THE ILLINOIS GLACIAL LOBE. 



several beds of sand and gravel associated with it. A prospect boring for 

 coal made at this city penetrated 189 feet of drift, as follows: 



Keel ion of boring for coal at Farmer City, Illinois. 



Feet. 



Black soil 2 



Yellow till 9 



Blue till 36 



Sand and water 



Blue till 21 



Sand and gravel - 4 " 



Blue clay 6 



Sand and gravel ° 



Sandy blue clay i0 



Sand and gravel "** 



Blue clay 2 



Total drift 189 



Several interesting well sections and bluff exposures are found along 

 the west side of the Sangamon River below Mahomet. About 1£ miles 

 southwest of this village, in sec. 16, T. 20, R, 7 E., the river exposes in its 

 northwest bluff a bed of peat under the Shelbyville till sheet; The expo- 

 sure is several rods in length and the section is as follows: 



Exposure in bin if of Sangamon River near Mahomet, Illinois. 



Feet. 



Yellow till with gravelly places near base, where springs issue 10-12 



Gray till with yellowish tinge 20 



Peat, earthy except 3 to 6 inches at top 2 



Gray earthy subsoil, exposed 2-3 



Total, to river bed 36 



It is probable that the Shelbyville sheet is reduced at this place to a 

 thickness of only 30 to 32 feet, as the altitude near the river is slightly 

 lower than the general level of the border plains. Wells between this 

 exposure and Mahomet pass through a black muck or peat at about the 

 same level as that exposed along the river. One on the farm of James 

 Lester strikes it at 36 feet, and one at the residence of D. Mc Arthur at 42 

 feet. Mr. McArthur's Avell was continued to a depth of 100 feet and pene- 

 trated a harder till below the black muck than that winch overlies it. There 

 are places between this exposure and Mahomet where the entire bluff is 

 composed of gravel. It is principally on the farm of Mr. Lester, and he 

 has tested its extent by means of borings and found that it underlies only 

 60 acres. Around the gravel on all sides except at the southeast, where it 

 fronts the river, there is till. Its depth is found to reach 50 or 60 feet in 



