84 
OIL AND GAS; OHIO, WEST VIRGINIA, PENNSYLVANIA. 
the anthracite region to the east. It was then depressed below water 
level and sedimentation was resumed, but the conditions were those 
of fresh or brackish water and the coarse conglomerates and sand¬ 
stones of the upper Pottsville were deposited. The eroded surface 
upon which they were laid down was somewhat irregular, and conse- 
quently the parallelism of the beds above and belov this line of 
unconformity is not exact. 
KEENER SAND. 
The Greenbrier limestone is usually divided into two sections by a 
small sand rock, which is known as the Keener sand. 
BIG INJUN SAND. 
The Pocono sandstone, which is known to the drillers as the Big 
Injun, has a thickness of 100 to more than 200 feet. Generally it is a 
fine-grained homogeneous sandstone, and is white, yellow, or almost 
any color, except red. In some localities there is a “ break ” or layer 
of shale in the lower part of this formation, which is spoken of by 
some drillers as the “ break in the Big Injun/' By other drillers the 
sandstone below the “ break " is regarded as a separate bed, and is 
called the Squaw sand. 
CUYAHOGA SHALE. 
The Pocono sandstone is underlain in Ohio by a soft blue and gray 
shale, more than 300 feet thick, which is known as the Cuyahoga, 
from its outcrop in Cuyahoga County, Ohio. 
BITTER ROCK SAND. 
In Pennsylvania a sandstone is present in the Cuyahoga shale at a 
point about 100 feet from the bottom. This sand is known as the 
Bitter Rock, from the large amount of salt water contained in it. 
SUNBURY (“ BEREA ”) SHALE. 
Below the Cuyahoga shale is a very dark or black shale, about 25 
feet thick, which lies directly above the Berea sandstone. This is 
known as the Sunbury shale, from its outcrop at that place, in central 
Ohio. 
BEREA SAND. 
The Berea sandstone, named by Newberry from the village of 
Berea, Cuyahoga County, Ohio, is the great oil-producing bed of east¬ 
ern Ohio. It is a fine-grained white sandstone. Generally the upper 
portion of the bed, for a distance of 12 to 20 feet, is cemented into a 
