1S2 GEOLOGY OP ILLINOIS. 



E con omical Geolo g y . 



Goal. — There are no thick beds of coal in this county, and excepting 

 "Nelson's," no workable beds. 



Mr. G. W. Nelson's coal bank is on a high prairie in sec. 20, T. 6 N, 

 E. 4 E. A pit has been opened, and good coal procured ; but when I 

 was there it was full of water, so that the thickness could not be cor- 

 rectly ascertained ; but I was informed that it was 3 feet. Six miles 

 down the creek, at Mahon's, it is 10 inches; and on Limestone creek, in 

 sec. 18, T.6B., 11. 5 E., it is 16 inches thick. These several outcrops — 

 the one at the head of the creek, the other six miles below in the bed 

 of the same creek — indicate a decided easterly dip. The same coal is 

 also found on Big creek, in sec. 25, T. 7 N., E. 4 E. At these several 

 places it is of variable thickness, and only separated from the overlay- 

 ing limestone by a few inches of clay. I have catalogued this coal as 

 No. 16, couuting from the lowest. Except at Nelson's, neither black 

 slate nor shale was observed overlaying it. At Nelson's the black shale 

 is calcareo-bituminous and fossiliferous. 



On Salt and Brush creeks there is a 6-iuch seam of bituminous coal, 

 which I have marked as No. 17 ; its sure guide is two thin, even layers 

 of gray limestone, occurring about 4 feet above, and aboundiug in 

 Spirifer plano-convexus. This coal was reported to me to be 16 inches 

 and 2 feet in thickness, but I observed it nowhere so thick. On Salt 

 creek, near the mouth of Brush creek, several "pits have been dug at 

 different times, but are now all full of earth and rubbish. 



A thin coal seam observed in sec. 26, T. 9 N., E. 5 E., may be referred 

 to either No. 16 coal, or else locally between 16 and 17 ; but I am iu 

 doubt regarding its exact horizon. 



Coal No. 15 is only found on Beech creek, a branch of Eock creek, in 

 sec. 30, T. 8 N., E. 4 E., one foot in thickness, with thick-bedded sand- 

 stone overlaying it. A shaft at Effingham, in order to reach coal No. 

 5, would have to be sunk about 900 to 950 feet. 



Iron ore. — The drift conglomerate occurring in sec. 17, T. 8 N, E. 5 

 E., is 3 feet thick, and contains a good deal of iron ore. It crops out 

 on a point of the hillside, extending for 30 feet across. A similar deposit 

 occurs near the mouth of Big creek, in sec. 30, T. 8 N., E. 5 E. Coal 

 Measure shales on Big creek abound in many concretions of oxyd and 

 carbonate of iron ; there are also some in other localities, but the quantity 

 is insufficient. 



The sandstone below Effingham, in the fossiliferous portion, is very 

 ferruginous. Eed oxyd of iron occurs on Beech creek in sandstone over 

 coal No. 15. 



