GENERAL STRATIGRAPHY OF THE REGION. 
73 
as to affect the usefulness of the stone for building* purposes. 
Remarkable variations in the thickness of the Washington sandstone 
may be noted in the cuts along the Baltimore and Ohio Railroad 
from 4\ ashington westward to Woodell station. Here the top of the 
bed, capped by the Washington coal, dips gently and evenly to the 
west, whereas the bottom of the bed, overlying the Little Washington 
coal, rises and falls in a series of undulations measuring from a few 
feet to 100 yards or more from crest to crest, the difference of thick¬ 
ness of the sandstone by this unevenness of its bottom being in places 
as much as 6 or 8 feet, though the usual range is from 1 to 3 feet. 
WASHINGTON COAL. 
The Washington coal lies not far from the middle of the Washing¬ 
ton formation. Next to the Pittsburg coal it is the most prominently 
outcropping and most easily recognized coal bed of the area investi¬ 
gated. It shows in outcrop in the southeast corner of the Steuben¬ 
ville quadrangle, in all townships south of the Panhandle Railroad 
in the Burgettstown quadrangle, and throughout the middle and 
northern portion of the Claysville quadrangle. 
The general thickness of the Washington coal bed is from 7 to 8 
feet. This total is made up by a succession of layers, about G inches 
thick, of coal and shale in the upper part of the bed and a bench of 
solid coal, from 2J to 3 feet thick, in the lower part. The seams of 
shale in the upper part of the bed seriously affect the economic value 
of the coal, but in no way detract from its value as a guide to geology. 
If the coal is exposed in section, it can be readily recognized by its 
lower bench, the shale and clay partings along the center of the bed, 
and the 4-inch seam at the top overlapping 1 to 2 feet of fire clay. 
LOWER WASHINGTON LIMESTONE AND ASSOCIATED ROCKS. 
Above the Washington coal is from 5 to 15 feet of coarse black and 
brown shale, which extends upward to the Lower Washington lime¬ 
stone. The bottom layer of this limestone is from 10 inches to 2 feet 
thick and bluish gray, with reddish streaks. The thickness and tex¬ 
ture of this layer differ greatly in many adjacent localities. It is, in 
general, rather argillaceous and in many places weathers to a bright 
yellow. Overlying it are several thin layers of limestone, having a 
total thickness of 2 or 3 feet. These rocks are usually gray in color 
and have a somewhat slaty cleavage. They are succeeded by 10 to 18 
inches of a yellowish-gray limestone, which shows on fresh fracture 
a steel-gray color. Overlying this limestone is from 5 to 6 feet of 
black or blue shale containing, in one or two places noted, a few inches 
of shaly coal. The next two limestone layers above this shale are 
of about equal thickness, amounting to a total of 4 to G feet. Both 
