158 GEOLOGY OF ILLINOIS. 



Up a small branch which enters Apple creek from the southwest, near the 

 center of the south line of section 27, I observed outcrops of shale, limestone, 

 etc., with a small vein of coal, in the following order. : 



FEET. 



1. Light colored, fossiliferous limestone , . 1 



2. Clay shale 3 



3. Black or dark colored shale or slate 10 



4. Light colored shale 8 



5. Coal 1 



6. Fire clay, exposed 4 



In one or two places, I observed an exposure of a few inches of shale in posi- 

 tion above No. 1 of this section, but not in contact. The fossils in the lime- 

 stones were generally imperfect and indistinct. In the shales below they are 

 easily obtained, and tolerably well preserved. The most abundant species ob- 

 served, were corals of the genus Cyathoxonia, Leda ventricosa, Astartella varica, 

 Pleurotomaria, Grayvillensis? an Orthoceras, etc. A little below the point at 

 which the foregoing section was taken, there is a continuous ledge of the shale, 

 from five to eight feet in hight, extending along the bank of the river for a 

 distance of twenty or thirty rods. Still farther up the ravine, in the northeast 

 quarter of section 34, the coal again outcrops, and still above this, near the 

 Macoupin county line, in the southwest quarter of section 35, there is an expo- 

 sure of ten or fifteen feet of shale, overlying the thin limestone, No. 1, of the 

 above section. 



North of these exposures, in the eastern part of the county, there are but 

 one or two points where the older rocks appear above the surface, or are artifi- 

 cially exposed. One of these occurs on the land of Mr. John Rohrer, in the 

 northeast quarter of section 25, township 13, range 8, where a reddish sand- 

 stone, in layers varying from two inches to a foot in thickness, has been quar- 

 ried as a building stone. The stone occurs in the bed of a small branch, run- 

 ning north into Apple creek, and four or five feet of gravel has to be removed 

 before reaching the valuable portions of the rock. To the northward of this, 

 in the vicinity of Waverly, sandstone is said to have been met with in digging 

 wells, at a depth of sixteen or eighteen feet possibly the same beds that are 

 exposed at this point. 



Near Prentice station, on the St. Louis, Jacksonville and Chicago railroad, 

 in the northeast corner of the county, a shaft has been sunk in the beds of the 

 Coal Measures, and the overlying Drift, to the depth of about two hundred and 

 twenty feet, and has been continued by boring over one hundred feet more. 

 As this affords the only means we have of judging of the Coal Measures in this 

 part of the county, it will, perhaps, be as well to give the section of the beds 

 passed through, in full, as reported to me. After eighty-five feet of Drift, the 

 variations of which have been already given in a previous portion of this chap- 

 ter, the order of the strata was as follows : 



