AN OCCURRENCE OF COAL WHICH BEARS EVIDENCE 
OF UNUSUAL CONDITIONS ACCOMPANYING ITS 
DEPOSITION’ 
JESSE E. HYDE 
School of Mining, Kingston, Ont. 
It is purposed to describe an occurrence of coal which is unique 
in its relationships to the overlying and underlying rocks and which 
shows by the structures in the associated sediments that it was 
deposited under conditions which were peculiar. Certain of these 
conditions differed widely from those which were usual to the 
accumulation of a continuous deposit of coal over a broad area, 
but it appears that certain other conditions which are suggested by 
the occurrence may have held during the accumulation of those 
coals which have been formed in the more usual manner. 
THE OCCURRENCE 
The occurrence is in a deep cut on the B. & O. Railroad at 
Sommerset, Perry County, Ohio. At either end of the cut a highly 
fossiliferous marine limestone is exposed, but throughout most of its 
length the bottom of the cut is not deep enough to reach it. This 
limestone, about 3 feet in thickness, is probably the Lower Mercer 
member of the Potsville formation. It is generally present in this 
region 75 or 85 feet above the base of the Pennsylvanian. 
Above the limestone is a bed of soft gray clay shale which is 
some 12 to 15 feet thick. It is overlain by a massive coarse sand- 
stone whose thickness is estimated at 20 to 25 feet. The upper 
part of the shale and this sandstone are exposed throughout the 
cut. The contact between them is very irregular, rising and fall- 
ing as much as 6 or 8 feet. In pockets at this contact, well shown 
for 300 yards in the deeper part of the cut, the coal under consid- 
eration is found. 
Above the sandstone there is a bed of shale 1 or 2 feet thick, 
overlain in turn by a second coal seam. Both of these are inacces- 
t Published by permission of the State Geologist of Ohio. 
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