EDGAR, FORD, AND CHAMPAIGN COUNTIES. 273 



FEET. 



Soft yellow clay 9 



Sand 3 



Yellow clay 7 



Quicksand and gravel 59 



179 



The bottom bed of quicksand defied all his efforts to reach a greater depth. 

 Within a short distance of this place, however, an earlier boring, of which we 

 have not the data, is said to have reached soft blue shale at one hundred and 

 sixty-eight feet from the surface. 



The depth and character of these beds correspond with what is known of 

 similar deposits to the northward and eastward. We find in them evidence 

 that, at some former period, some powerful denuding current has torn up the 

 rocks and excavated a broad and deep channel, extending from the southern 

 end of Lake Michigan, down the eastern line of the State until, shortly after 

 passing the line now occupied by the Kankakee river, it rose over the declining 

 edge of the Niagara limestone, and then bore off southwestward through the 

 softer beds of the Coal Measures, which here seem to lie directly upon the 

 Niagara. This channel passes through the central and western parts of Iro- 

 quois county, and includes large parts of Ford, Champaign and McLean coun- 

 ties, with the southeastern part of Livingston, where its western bank must be 

 located between the two borings at Chatsworth, the western, on the southeast 

 quarter of section 4, township 26 north, range 8 east, near the east line of the 

 section, striking the Coal Measure rocks at eighty-eight feet, and the eastern, 

 in the southeast quarter of section 3, of the same township, striking no rock 

 until it reached the green calcareous shales of the Cincinnati group at two 

 hundred feet. 



To the westward of Champaign county, its course is not so well indicated; 

 we know only that it runs under Bloomington, in McLean county, with a depth 

 of two hundred and fifty-four feet. However, as we find at Rantoul and Cham- 

 paign, points probably near the eastern side of the channel, and at Chatsworth, 

 which we know to be on its western bank, only one "dirt bed," or ancient 

 mucky soil, noted as "peat" in the foregoing section, while at Bloomington 

 we find two such beds well developed, one six feet, and the other, thirteen feet 

 thick, I am inclined to believe that this point is near the center of the old val- 

 ley. I will further suggest that its junction with the valley of the Illinois 

 will probably be found somewhere in Tazewell or in Mason county. 



The erosion of this great valley, of course, took place before the beginning 

 of the Drift period, since the deposits of that age not only fill it completely, 

 but deeply cover its banks, except at the few points where they have been re- 

 moved in the course of the erosion of the present river valleys. 



35 



