82 
OIL AND GAS; OHIO, WEST VIRGINIA, PENNSYLVANIA. 
The Lower Kittanning coal is not generally mined for commercial 
purposes, owing probably to the high percentage of sulphur which it 
contains. The clay below the coal is extensively developed and used 
for the basis of a large pottery business along Ohio River. 
POTTSVILLE FORMATION. 
The Pottsville formation includes the rocks from the Homewood 
sandstone to the unconformity described on page 15. In this region 
the Pottsville was deposited upon a subsiding land area, which con¬ 
sequently had a migrating shore line. For this reason it generally 
consists of coarse sandstones and conglomerates that were thoroughly 
washed by the waves and currents. The finer sediments were sorted 
from the coarse material and carried far out into deep water, while 
the coarser sediments were deposited along shore. 
HOMEWOOD SANDSTONE. 
The Homewood sandstone, the uppermost member of the formation, 
is probably represented in the well records by the Gas sand. This 
may be true, however, only in part of the records, and in others the 
sand called the Gas sand may be the equivalent of the Connoquenes- 
sing sandstone below the Mercer coal. 
MERCER COAL. 
In the records of some of the deep wells in the northern part of the 
Steubenville quadrangle are notes of one or two coal beds above the 
Salt sand. It is difficult to class these coals, owing to the lack of 
detailed information, but it seems probable that they occur below the 
base of the Allegheny formation, and, therefore, possibly represent 
the Mercer coal beds of the Beaver Valley in western Pennsylvania. 
In the type locality the Mercer coals occur between the Homewood 
and Connoquenessing sandstones, but in the Steubenville well records 
no sandstone is noted immediately above the coals, and hence it seems 
probable that the Homewood sandstone is not extensively developed 
in this region. The data are not sufficient to make definite correla¬ 
tions, but the preponderance of evidence seems to indicate that these 
are Mercer coals. 
SALT SAND. 
The Salt sand is a coarse white sandstone 20 to 30 feet thick. Usu¬ 
ally it is saturated with salt water, and from this condition it receives 
its name. Below the Salt sand is an irregular bed of shale ranging 
in thickness up to 20 feet. With the evidence at hahd it is impossible 
to say whether this bed is a part of the Pocono sandstone or whether 
