498 GEOLOGY OF OHIO. 
places, yet it is quite certain that he must follow pretty closely certain 
lines. Any considerable variation from such general lines will necessi- 
tate failure. The first well was bored here by Mr. John Newton and his 
associates in 1860. They were first drawngto this region by an oil spring, 
it is said. This well continued productive for eight or ten years, and 
yielded many thousands of barrels of oil. Many other excellent wells 
have been obtained. The field is a very small one—perhaps not much 
more than: half a mile along the axis of the uplift, and probably less 
than that on a line at right angles to the axis. Some years eighty 
thousand barrels have been produced. No oil field in Ohio has been so 
valuable as this. The Cow Run uplift is entirely disconnected from the 
great West Virginia oil uplift, which crosses the Ohio River a little 
above the mouth of Newell’s Run, Newport township. Itis an entirely 
independent uplift, doubtless, however, produced at the same time and 
by the same forces which produced the one on Newell’s Run, and, indeed, 
caused all the undulations of the Coal Measure rocks in south-eastern Ohio. 
When the uplift took place there were more or less subterranean cracks 
formed, extending to great depths. In these fissures the oil from below 
coming up in the form of vapor, from the distillation of bituminous ma- 
terials underneath, accumulated. The cracks in the sandrocks remained 
open—for the walls would not be disintegrated by water—and retained 
the original oil, while the cracks in strata of clay shales, or ““mud rocks,” 
would, as water entered them, be filled with the mud of the disinte- 
grating shales, and thus ultimately the oil would come to be found 
chiefly in sandrocks. Whether there are now any unclosed fissures ex- 
tending down to the prime sources of oil, so that the supply is con- 
stantly accumulating, is doubtful. Wells are often pumped with some 
success after having been once exhausted, but the oil is doubtless brought 
in from the connecting fissures in the same sandrock, and not from great. 
depths below. The fact that we find nearly all the oil Tepainened in fis- 
sures in sandrock would imply that it is old oil. 
There is a group of limestones on the bank about thirty feet above the 
Little Muskingum, at the mouth of Fifteen-Mile Creek. When there 
many years ago it was reported there was a seam of coal about thirty 
feet above the limestone, while about one hundred feet above the lime- 
stone was another seam under a sandrock, supposed to be the equivalent 
of the upper Salem, or ‘‘sandstone seam.” During the progress of the 
survey I had no opportunity to revisit the location. 
On Bear Run a thin seam of coal—reported fifteen inches thick—was 
seen on the land of Mr. Atkinson, section 2. This may possibly be the 
Hobson seam, but its exact stratigraphical position could not be deter- 
