78 OIL AND GAS; OHIO, WEST VIRGINIA, PENNSYLVANIA. 
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DUNKARD COAL AND ASSOCIATED ROCKS. 
About 125 feet above the bottom of the Greene formation there 
is a fairly persistent but thin layer of bituminous shale which 
locally occurs as a coal bed a few inches thick. This is probably the 
Dunkard coal, as named by Stevenson,® though the fewness of the 
exposures noted makes this correlation somewhat doubtful. 
For 100 to 125 feet above the Dunkard coal bed are reddish lami¬ 
nated sandstones and shales, in which two or three thin beds of 
limestones occur. At one or two places in the vicinity of East Fin- 
lev a small coal smut was noted in these rocks at about 155 feet above 
the top of the Upper Washington limestone, but the bed appears to 
be only of local extent. 
CLAYSVILLE LIMESTONE AND ASSOCIATED ROCKS. 
From 205 to 225 feet above the base of the formation lies a lime¬ 
stone, separated into two layers by G to 8 feet of yellow shale. The 
to]) layer is from 6 to 8 inches thick, bluish white, and dark brown 
on fresh fractures. The bottom layer is here and there as much as 
18 inches thick, weathers with a rough surface to a reddish or yellow 
color, and is a dark gray on fresh fracture. This limestone is present 
over a considerable area in the southern and western parts of the 
Claysville quadrangle. In the northern part of East and West 
Finley and Morris townships it is a rather compact bed, from 6 to 8 
feet thick, the top layers being heaviest and all having a dark-gray 
color. Since it can not be correlated with any bed previously named 
and is among the most prominent limestones of the Greene formation 
in this section, it has been thought advisable to call this bed the 
Claysville limestone, from the town of that name in Donegal Town- 
ship, Washington County. 
Above the Claysville limestone are 50 or 60 feet of reddish and 
dark-colored shales, in which at irregular intervals are embedded thin 
sandstone layers. These shales are overlain at many places by 2 to 
G feet of light-gray to brown limestone. The top layer is heaviest, 
and on fracturing is light buff; the lower layers are very thin and 
easily disintegrate to small gray nodules. Above this limestone is 
a few inches of carbonaceous shale and 25 or 30 feet of reddish 
shales, capped by 10 or 15 feet of thin grayish laminated sandstone. 
NINEVEH COAL AND LIMESTONE. 
About 325 feet above the base of the Greene formation and 100' 
feet above the Claysville limestone is a rather persistent coal bed, 
fiom G inches to 1 foot in thickness. This is probably the Nineveh 
a Stevenson, J. J., Second Geol. Survey Pennsylvania, Rept. K, 1876, p. 35. 
