554 GEOLOGY OF OHIO. 



to one hundred and seventeen feet. These facts show conclusively that 

 the successive subsidences were not continental, but occurred along the 

 lines of neutral axes, giving a wedge-shaped form to many of the strata. 

 Indeed, had those subsidences been continental, the lower coal would 

 every where be buried beneath all the other members of the Coal Measure 

 rocks, except where the latter had been carried away by erosion, and the 

 last coal deposited would extend farthest up the slopes of the hills which 

 bordered the coal territory, and would be the first encountered upon ap- 

 proaching the coal field. 



The outcrops of this coal are found in every township and upon the 

 slopes of almost every hill, and generally with evidences indicating a 

 remarkable thickness, but few of them have been satisfactorily tested. 



Iron Ore. — Just above this horizon are deposits of iron ore extending 

 over most of the county, from which large quantities could be mined 

 should there be a sufficient demand for it. In places the slopes of the 

 hills between this coal and the next above, are covered with the ore; and 

 on John Simmons's land, in Knox township, where these fragments are 

 very abundant, it is reported that a solid deposit of ore eight feet thick 

 was penetrated in sinking a well. 



Coal No. 3a. — A sandy shale separates the blue limestone from the coal 

 designated as No. 4 in the preliminary report on this county, but which, 

 from its unimportant character throughout the State, is now designated 

 as No. 3a. The interval ranges ordinarily from eighteen to thirty feet ; 

 but in Salt Creek township measuretaents have been made where it is 

 fully seventy feet. 



Nowhere in the county have I found this coal of sufficient thickness to 

 be profitably mined, although its outcrops are numerous and its horizon 

 can be accurately determined in nearly all parts of the county. On the 

 Killbuck Coal and Mining Company's property, in Mechanic township, 

 it is associated with iron ©re in the overlying shales, and it is possible 

 that further explorations may show that the two minerals can be profit- 

 ably mined together. The limestone which overlies it in parts of Coshoc- 

 ton county, appears occasionally in the eastern part of Holmes, and care 

 is required not to confound it with the blue limestone below. 



Coal No. 4. — The shales and sandstones between the last and Coal No. 4, 

 or the grey limestone seam, range from twenty-five to fifty-five feet in 

 thickness. The material is generally a thin-bedded shaly sandstone of 

 no value, but in places it would furnish fair flagging stone. This coal 

 attains its maximum thickness, in the county, in Salt Creek township, 

 where it is three and a half feet thick, with six feet of limestone resting 

 directly upon it. Very good coal can be obtained from the openings here, 



