724 WEOLOGY OF OHIO. 
tance from the Pittsburgh coal to the crinoidal limestone is 207 feet, and 
to the shaft coal is 511 feet. At LaGrange the interval is 540 to 550 feet. 
The interval between Coals No. 6 and No. 8 is 512 feet, as measured by 
barometer. 
The hills which form the banks of the Ohio at Pittsburgh are geo- 
logically the same as those at Steubenville, and those who have noticed 
the great thickness of olive and gray shales which chiefly form them, 
with nothing of interest or value below the Pittsburgh coal and above 
the Ohio, will perceive the appropriateness of the term chosen by Prof. 
Rogers to designate them. ; 
As has been stated, the coals of the Barren Measures are generally of 
little or no value, but on Wills Creek the coal under the crinoidal lime- 
stone, about two hundred and twenty-five feet below the Pittsburgh 
seam, is two and a half feet in thickness, and of very good quality. This 
is Coal No. 76 of our series, and is that worked at Harlem, in Carroll 
county. There are a few places in the northern part of Jefferson where 
it is worth working. South of the railroad it is generally but a few 
inches in thickness, and has no economic value. 
THE LOWER COAL GROUP. 
In all the northern part of the county five workable seams of the 
Lower Coal Group lie above drainage, and are opened and worked in 
many places. These are Coal No. 7, locally known as the “Groff Vein” 
and “Salineville Strip Vein;” Coal No. 6, the “Big Vein;” Coal No. 5, 
or the “Roger ;” Coal No. 4, the “ Hammondsyille Strip,” and Coal No. 3, 
the “Creek Vein.” The latter lies about thirty feet above the Ohio, at 
the mouth of Yellow Creek, and runs along the river bank at about the 
same level to Sloan’s Station. Here a rapid southerly dip begins, which 
soon carries all the lower coals beneath the surface. 
Borings and shafts in the northern part of the county have revealed 
the presence of two, or, sometimes, three thin coal seams within a hun- 
dred and fifty feetof the “Creek Vein,” but, so far as known, these are 
nowhere of workable thickness. Deeper borings, of whieh a large num- 
ber have been made for salt and oil in the northern part of Jefferson 
members of the Geological Corps. Since it is impossible in this vicinity to obtain a 
vertical section, the outcrops of the Pittsburgh coal being west of the river, while the 
shafts are located on the river bank and down a south-easterly dip, the true distance 
between the two coals has been doubtless somewhat exaggerated. The sections at 
LaGrange and Rush Run are, however, so nearly vertical that there is no great liability 
of error from the cause cited above, and the distance as measured there between the 
Pittsburgh and shaft coals—a little over 500 feet—is probably about the average for 
this region, 
