TAZEWELL, M LEAN, LOGAN, AND MASON COUNTIES. 183 







Farther to the eastward from this point, and higher in the bluffs, I observed 



limited exposures of a reddish, shaly sandstone, or arenaceous shale, which 

 seems, from its position, to overlie the uppermost beds of the above section. 



In the vicinity of Pekin, there are but few natural exposures of the under- 

 lying rocks, but the lower coal is mined at several points in the neighborhood 

 of the city. The coal is generally overlaid by black slate, with, as is stated, in 

 some cases a foot or two of limestone. Above the slate there is generally from 

 twenty to forty or fifty feet of sandstone or sandy shales, according to the lo- 

 cality of the shafts on the edge of the bluffs, or farther up towards the rolling 

 upland. This sandstone may be seen in the bottoms of ditches at one or two 

 points along the Tremont road, about a mile east of the city of Pekin, and in 

 the immediate vicinity of the principal coal mines. 



At Mr. Hawley's place, about five miles southeast of Pekin, a shaft was 

 sunk, which passed through both the upper and lower coals, affording a section 

 of the intermediate beds, which, as reported to me, was as follows: 



FEET. 



1. Argillaceous shale .... 4 



2. Light colored limestone 2 



3. Coal 4 



4. Fire clay 8 



5. Sandstone . . , 50 



6. Bluish black slate 4 



7. Coal 4 



8. Fireclay 8 



About ~wo miles east of Mr. Hawley's place, in the southwest quarter of 

 section 20, township 24, range 4, on a branch called Lost creek, there is said 

 to be another exposure of brownish sandstone, of very limited extent. I failed 

 to find this locality myself, but if a sandstone occurs here, it may be that over- 

 lying the lower coal, or possibly a still higher bed, not represented in the above 

 section. 



In the central and eastern portions of Tazewell county, there are a few 

 localities where borings, etc., have been made, but satisfactory records of the 

 variation in the strata could not in all cases be obtained. At Rapp's mills, near 

 the center of the north line of section 20, township 24, range 4, a shaft was sunk 

 to the depth of eighty-five feet, and, as it was reported to me, struck limestone 

 at that depth. If this be the case, it was very possibly the limestone overlying 

 the upper coal, but, without more reliable data, it is impossible to speak with 

 certainty. The shaft was abandoned before completion, on account of the 

 difficulty of keeping it free from water. At Delevan, in the southeastern por- 

 tion of the county, a boring was made, which was reported to have passed 

 through sixty feet of sandstone, and, below that, seventy-five feet more of 

 arenaceous and argillaceous shales. No coal was reported in this boring. 



