204 GEOLOGY OF OHIO. 
somewhat more large coal from the main seam. The structure is repre- 
sented in Fig. XXX: 
FIGURE XAA 
STRUCTURE OF BRUSH CREEK COAL 
(N27 OF NEWBERRY) OR STRIP VEIN 
AT SALINEVILLE. 
Rack Slate pees ee ————— Oils 
Cea es at ie iklaa! 
Poxtind -~-- ---~-~-—---_ & 
Goal ( poor} Ee ee eee WW 
Choy Peete eee eng Seen supra ren Se 43h 79) 
Lumestoue_.___ eee By 
There have been already about 400 acres of the Strip Vein worked 
out in the immediate vicinity of Salineville. At present five mines are 
in operation with a capacity of about 500 tons daily. 
The work now done, however, is small, and with the present state 
of the market, the seam could not now be opened. It is only where 
the plant is already made that the working of the seam goes forward. 
It is claimed that the clays and rock between the Strip Vein and 
Big Vein prevent the unwatering of the Strip Vein by the withdrawal 
of the lower seam. If this claim is well founded, the upper coal can 
_ abide its time, but if the water is gradually lost, the air will follow and 
take its place, and will thus greatly deteriorate, if it does not destroy, 
the value of the unworked seam. 
The seam holds a large area throughout the district of which 
Salineville is the center in Columbiana, Carroll, and Jefferson counties. 
This is the region of its best development in Ohio, and the only region 
in the State where it is mined on the large scale. Its general thickness 
in the county outside the Salineville field is 30 inches, but it is almost 
everywhere a strong, clean coal. 
The Roger or Lower Freeport coal has been named as.an element 
in the Salineville district. Its horizon is not generally reached in the 
immediate vicinity of the town, its normal place being about 40 feet 
