14 DRIFT DEPOSITS OF ILLINOIS. 



Dry sand and pebbles were thrown out upon the surface by 

 the pressure of the gas, indicating the presence of sand and 

 gravel beds beneath the green clay, the gravel beneath and the 

 clay above furnishing the necessary conditions for the reception 

 and retention of the gas, which was probably generated in the 

 bituminous shales of the coal measures beneath. 



The well at the railroad station at Odell, in Livingston county, 

 passed through the following beds, according to the record as 

 reported, without reaching bed rock: 



Ft. In. 



Soil and yellow clay 9 



Blue clay (boulder clay) 66 



Gravel and sand 5 



Blue clay 15 



Gravel and sand 2 



Blue clay 8 



Gravel 4 



Blue clay 22 8 



Gravel 4 



Blue clay 2 



Total 130 4 



The coal shaft at Bloomington, in McLean county, was carried 

 down through the thickest deposit of superficial material pene- 

 trated by any coal shaft in this State. This extraordinary 

 thickness of drift fills the old channel, already mentioned, by 

 which the waters of the great lakes found an outlet into the 

 valley of the Illinois river, and thence, through the valley of 

 the Mississippi, into the Gulf of Mexico. The following is a copy 

 of the record of the superficial material in this shaft: 



Feet. 



Soil and brown clay 10 



Blue clay 40 



Gravelly hard pan (boulder bed) (iO 



Black mucky soil 13 



Clay hard-pan 89 



Black soil 6 



Blue clay 34 



Quicksand 



Total 254 



The wood found in the mucky soil at the depth of one hun- 

 dred and ten feet proved to be in a remarkably fine state of 

 preservation, and belonged apparently to a species of cedar. 

 The quicksand at the bottom of the above section contained 

 the comminuted fragments of terrestrial arid fluviatile mollusca, 



