74 
OIL AND GAS; OHIO, WEST VIRGINIA, PENNSYLVANIA. 
are somewhat cherty, have a steel-gray color on fresh fracture, 
changing to light gray when exposed to weathering, and disintegrate 
very readily into small, roughly cubical blocks. 
Directly overlying the Lower Washington limestone is a bed of 
dark to black fossiliferous shale from 1 to G feet thick. Near the 
bottom of this shale there is exposed in numerous localities a thin bed 
of shaly coal, which, at a few places near Taylorstown in the Clays- 
ville quadrangle, attains a thickness of about 18 inches. This black 
shale is capped by G or 8 feet of yellowish shale, which merges into 
a reddish thin-bedded sandstone, usually from 5 to 20 feet thick. 
This sandstone varies greatly in thickness, in places being massive 
and filling the entire interval between the Lower and Middle Wash- 
ington limestones, with the exception of a few inches of black and 
yellow shales at the top and bottom. In an old quarry once operated 
by the Baltimore and Ohio Railroad, on Buffalo Creek, one-fourth 
mile south of the u S ” bridge, the bed is between 40 and 50 feet 
thick, with a single 20-foot layer near the bottom. Above this sand- 
stone is usually 4 to 6 feet of brown shale to the bottom of the Middle 
Washington limestone. 
MIDDLE WASHINGTON LIMESTONE. 
The Middle Washington limestone lies from 50 to 65 feet above 
the Washington coal. It consists of several limestone layers sepa¬ 
rated from each other by a few inches to 2 or 3 feet of shale, and 
having a total thickness of 10 to 30 feet. There are but four layers 
in the bed that are at all easily recognized—a 2 to G inch deep-pink 
ledge at the bottom, two yellow ledges about the middle, and near 
the top a 6 to 8 inch cream-white layer which has a dark mottled 
color on fresh fracture, the white appearing on the outside as if the 
stone had been painted. The yellow layers are from 1 to 2 feet 
thick. The lower one is about double the thickness of the upper, is 
very prominently exposed, and may be easily recognized by its tend¬ 
ency to exfoliate when exposed to weathering. The other layers 
of the bed are usually from G inches to 24 feet thick, in color bluish 
to gray and steel gray on fresh fracture. 
For about 35 feet above the Middle Washington limestone the 
rocks are, in the main, shaly sandstones, which at places occur in 
massive layers from 3 to 5 feet thick. Above these sandstones is 
usually from 5 to 15 inches of soft shaly coal (the Jollytown coal of 
Stevenson a ) of no geologic or economic value. This coal is over- 
lain by 50 to G5 feet of yellowish to reddish shales and sandstones 
that extend to the bottom of the Upper Washington limestone. 
Stevenson, ,T. J., Second Geol. Survey Pennslyvania, Kept. K, 1876, p. 48. 
