536 GEOLOGY OF OHIO. 



The middle bench, of three feet five inches, is a hard, bright, pure 

 coal, nearly dry burning, containing a moderate amount of ash, and but 

 little visible sulphur ; the upper bench is rather shaly. This is an un- 

 usually good opening of the Blue Limestone coal. The limestone which 

 covers it is ordinarily found at its proper horizon in the hills of all the 

 coal territory south of the Pittsburgh, Fort Wayne, and Chicago Railroad, 

 and is generally of good quality. In most places the coal is too thin to 

 work. 



For twenty to twenty-five feet below this seam, traces of Coal No. 2 

 have been frequently observed, and a few inches of coal have been dis- 

 closed at this horizon, in boring for No. 1, but I have no where found 

 promise of its being of any economic value. 



Coal No. 1 is the most valuable mineral deposit of the county. The 

 two mines of the Silver Creek Mining Company had, at the time of my 

 visit, an aggregate daily capacity of five hundred and fifty tons. The 

 coal ranged from four to five feet in one bench, has little sulphur, a small 

 percentage of ash, a large amount of fixed carbon, and is, in all respects, 

 a first-class bituminous coal. Considerable territory in ihe township is 

 underlaid by it, and the "Blue Chippewa coal" has become well known 

 in northern Ohio and is rated among the best. The result of five borings 

 give an average of four feet three inches of coal. 



The sandstone which overlies this seam extends several miles west of 

 Marshall ville, and probably to the great valley of erosion, through which 

 flows that branch of Chippewa Creek which has its origin in the swampy 

 region near Orrville. In this western extension of the coal works, only 

 thin coal has yet been found, and, in places, the sand-rock bflonging 

 above the coal is to be seen resting directly on the Waverly. 



The following section was obtained a little north-west of Marshall- 

 ville : 



FT. 



Coal sandstoue 25 



Sandy shales, Ijottom clearly WaTerly 50 



The line of division is here not well defined, but the coal sandstone 

 evidently rests directly on the Waverly, there being no coal shale or fire- 

 clay in the section. The rock at top is in thick, massive layers, becom- 

 ing thinner at the base of the upper twenty-five feet. Below the layers 

 are thinner beds of finer materials, with many ripple-marks and without 

 fossils, the ravine giving substantially a full exposure to the bottom, 

 where the layers are more evenly bedded and carry a few Waverly fos- 

 sils. This western extension of the coal-fields has been partially ex- 

 plored by boring, without disclosing workable beds, but it is by no means- 



