114 GEOLOGY OF ILLINOIS. 



thickness. The upper seam is from 15 to IS inches thick, and is under- 

 laid by a sandy fire clay with Stigmaria, passing into a hard nodular 

 sandstone, below which there is a bed of dark steel-gray, tough lime- 

 stone, weathering to a rusty brown color, and closely resembling that 

 underlaying the upper seam at Murphysboro. It is from eighteen 

 inches to two feet in thickness here, and contains joints of Grinoidea 

 and Sjririfer cameratus. The coal is overlaid by a massive sandstone, 

 partly concretionary and partly in regular layers, that is quarried for 

 building stone, for which it seems well adapted. The following is a 

 section of the bluff at this point : 



Ft. In. 



Quartzose sandstone 20 to 25 



Coal 1 3 



Silicions fire-clay 2 



Hard steel-gray limestone 1 6 



Slope with partial ouicrops of shale 40 



Bituminous shale A 2 



Coal 3 



Covered slope to the railroad level 20 to 25 



The coal obtained from the lower seam here contains a good deal of 

 iron pyrites, and in quality is rather below the average of our Illinois 

 coals, but it answers tolerably well for steam purposes. 



At the crossing of Sugar creek, about three miles north of Bolton, 

 on the Marion road, a massive sandstone outcrops in the banks of the 

 stream extending to the bight of fifteen to twenty feet above the creek 

 level, overlaid by a thin bedded sandstone, of which about the same 

 thickness could be seen. A coal seam has been opened here beneath 

 the sandstone and some coal taken out for blacksmiths' use, but it was 

 hidden by the high water when I was there, and hence I could neither 

 determine its thickness nor ascertain the quality of the coal it afforded. 

 This is probably coal No. 4 of the general section. 



At the water mill on the south fork of Saline river, about two miles 

 below the bridge on the road from Bolton to Marion, another seam of 

 coal is found associated with the following beds : 



Ft. In. 



■Brown sandy shale 4 to G 



Band of hard bluish-gray limestone 6* 



Bituminous shale 5 



CoalNo.5 2 



Nodular clay shale 2 



The brown shale at the top of the foregoing section may be seen in a 

 hill side near the mill -where it is about twenty feet thick, and its full 

 thickness is probably as.much as forty to fifty feet. The coal at the 

 mill is rather hard and splinty, but is said to work well in the forge. 

 The upper four inches is a cannel coal. This mill is located on the S. 

 E. qr. of the N. W. qr. of sec. 4, T. 10 S., R. 4 E. 



At the bridge over the South Fork, two miles above the mill near the 

 old town of Sarahsville, a thin coal outcrops by the side of the road, 



