240 GEOLOGY OF OHIO. 



i of section was observed only in Union township, between 



New Concord and Norwich. The limestone underlying it is more or less 

 fossiliferous. I was at one time inclined to regard this as perhaps the 

 western prolongation of the Pittsburgh, but no proof has been found to 

 substantiate the conjecture. The coal is of no value. 



The Crinoidal limestone is fully described in the report on Guernsey 

 county. In ^luskingum it is shaly and coarse-grained, wanting the 

 compactness and flintiness characteristic of it in Guernsey, Harrison, 

 and Carroll. It is well exposed in Highland, Monroe, Adams, and Salem 

 • townships, and runs out in the hills of Madison, about three miles east 

 of the river. The only species found here, aside from those given in the 

 list from Guernsey, is Ctenoptychius semicircularis, of which a single speci- 

 men was obtained in Salem township. 



Coal No. 7& is seen at a distance of from one to thirty-five feet below 

 the limestone. It appears to be of economical importance only in the 

 vicinity of Norwich, in Union township, where it is thirty- four inches 

 thick. Toward the north it becomes thinner, and averages only ten 

 inches through Salem, Adams, Monroe, and the greater part of High- 

 land. Where of available thickness, it appears to be a very good coal. 



The coal which I have termed the "Norwich" coal is quite circum- 

 scribed in area. Both it and the underlying limestone disappear north- 

 ward. It is worked in Highland and 'Union townships to a slight ex- 

 tent. The limestone under it is blue, weathering buff, verj-- tough, and 

 contains many fossils, among them Productus coBtatus,? P. punctatus, P. 

 longispinus, P. Praitenanvs, Athyris svhtUita, and Chonetes granulifera. 



Coal No. 7 is as variable here as in the adjoining county of Guernsey. 

 South of the Central Ohio Eailroad it attains great importance, but thins 

 out abruptly northward, being seldom more than one foot thick, and 

 usually a cannel of poor quality. At one or two points it suddenly ex- 

 pands to nearly six feet, but yields an inferior coal. It was seen in Mon- 

 roe, Adams, Madison, Washington, and Muskingum townships. 



Coal No. 6 is the important bed of the county. It is the upper coal at 

 Coaldale, near Zanesville, and is mined extensively in Monroe, Adams, 

 Madison, Washington, and Muskingum. The thickness varies from three 

 to four feet. The upper part of the bed usually consists of hard, slaty 

 coal, four to six inches thick, burning well, making a hot fire, but leav- 

 ing much ash. Six to ten inches from the bottom is a very persistent 

 clay parting about two inches thick. Other partings are sometimes seen, 

 but they are not persistent. Ordinarily the coal is of excellent quality, 

 containing little sulphur and yielding a very superior coke. In some 



