4, GEOLOGY OF OHIO. 
massive sandstone, which is prone to run into conglomerate, though the 
pebbles it contains are rarely larger than beans. This sandstone, which, 
from its development on the upper Stillwater, we have called the Still- 
water sandstone, in some places so much resembles the Mahoning sand- 
stone below, that the two have been confounded, and the coal seams Nos. 
7 and 6, which hold the same relative position to these two sandstone 
beds, have been mistaken one for the other. It is, however, generally 
not difficult to distinguish the two groups, for coal No. 7, in Tuscarawas 
county, nearly always thin, has almost invariably an important deposit 
of iron over it, either blackband, “ mountain,” or kidney ore, and at no 
great distance above it, the red shales may usually be found. An excel- 
lent exhibition of No.7 and its strata, can be seen in the divide between 
New Philadelphia and New Cumberland. On opposite sides of this 
divide, the valleys cut down to the Putnam Hill limestone, so that going 
from either, the starting point is the same. The best section is obtained 
from the New Philadelphia side. Here the limestone lies just in the 
bottom of the valley, above which are Coal Nos. 5 and 6, in their normal 
places—the first thin, the latter from three to five feet thick, and good. 
About one hundred feet above this, Coal No. 7 may be seen in the road, 
apparently not more than two feet in thickness; over this the kidney 
ore, and in places the mountain and blackband ores, forms of this iron 
deposit which frequently alternate. 
Above the iron horizon, lies a bed of red, yellow and mottled shale, of 
which the colors are bright and striking; a formation characteristic of 
this level. Over the shale is the Stillwater sandstone, kere compara- 
tively thin, but in part a well marked conglomerate. Above this, a 
heavy mass of olive shales, the typical barren measure material, reaches 
one hundred feet higher to the top of Mt. Tabor. 
Blackband and Mountain Ore—The blackband ore of Tuscarawas county 
has been so fully investigated during the forty years through which it 
has been sought and worked, and so fully described in our reports, that 
comparatively little will need to be said of it here. It is already known 
to most persons that this variety of ore is simply a black bituminous 
shale impregnated with iron. The degree of impregnation varies 
sreatly ; most of our black shales contain some iron, but generally too 
little to have any value as ores. In those varieties which are classed as 
blackband ore, the quantity of metallic iron varies from twenty-five to 
forty per cent. 
To an uneducated eye this material has very little the appearance of 
an iron ore, and would be, and doubtless has been, frequently passed as 
simply a black shale. It is highly charged with carbonaceous matter, 
