272 GEOLOGY OF OHIO 



quently taken no distinctive name, but it can be recognized in a coarse 

 and uneven-bedded sandstone, containing many coal plants, in a thou- 

 sand sections. From point to point, around the margin of our coal field, 

 these elements can be traced, and they thus constitute an identifiable 

 framework, which has its bodily extension to the eastward into Penn- 

 sylvania, and to the southward into Kentucky and West Virginia. The 

 Serai conglomerate in Ohio can be counted as 250 feet in thickness. 

 The coal seams included in this series, are the following: 



Tionesta. 

 Upper Mercer. 

 Lower Mercer. 

 Quakertown. 

 Sharon. 



The Sharon Coal. — This, the lowest coal seam of Ohio, was for 

 twenty-five years, in the early days of our mining interests, our most 

 valuable deposit of fossil fuel, but the seam has been almost exhausted 

 and it no longer holds an important place in the enumeration of our coal 

 resources. 



The peculiarities of its occurrence have been well described in pre- 

 vious reports of the Geological Survey. Dr. Newberry, in particular, 

 made a special study of this seam in its economic and geological features. 

 His descriptions of the seam and its mode of occurrence leave little to 

 be desired. (Volume I, page 214; volume II, page' 126.) He showed 

 that the Sharon coal in Ohio was formed in basins, excavated in the sub- 

 carboniferous rocks and that consequently, continuity of the seam on a 

 large scale does not exist. In volume V, much additional information 

 is given as to this coal deposit. (Volume V, pages 156, 169, 773, 1011.) 



No mapping of the areas of the Sharon coal has been attempted in 

 connection with the present report, because of the rapidly approaching 

 exhaustion of the seam in all its known areas. In Trumbull and Mahon- 

 ing counties, the work of mining coal in the large way has almost come 

 to an end. There is at present but a single large mine left in this once 

 prolific field. A few small areas remain, mainly in connection with the 

 older mines, but no considerable body of untouched coal of good thick- 

 ness is now known, although explorations have been carried on in a very 

 thorough and extensive manner through the entire region in which the 

 coal could reasonably be looked for. 



In Portage county, there is still some activity in the mines of this 

 seam. The Palmyra district supports four or five mines, and explorations 

 to the eastward show some areas of coal which will probably prove thick 

 enough for mining. 



In Summit county, mining has practically ceased, though it was the 

 center of an important production for 25 or 30 j T ears. 



In Medina county, a small amount of coal is mined in the Wads- 

 worth district and several new areas have recently been brought to light. 



