E. B. Andrews on Petroleum in its Geological Relations. 37 
the same time. The eae action along this line of uplift 
must have been very great, as, in some places, not less than a 
thousand feet of the jee -measures have been eroded. I can, 
however, find no traces of any other agency of erosion than those 
now at work, viz., atmospheric and aqueous. From West Vir- 
ginia this line of disturbance passes into Ohio, crossing the Ohio 
river near Newport, Messrs C03 OS but, farther to the 
Little Muskingum river, is exactly in the anticlinal axis of one 
of these smaller undulations. ‘This well began to flow in June, 
1861, and is, I believe, still flowing. It is 200 feet dee 
I have thus discussed the relation evidently existing between 
lines of geological disturbance and the production of oil in West 
Virginia and southern Ohio. <A similar connection has been 
observed by Sir Wm. E. Logan in the oil fields of Canada (Ge- 
ology of Canada, p. 379). The oil obtained on the upper Cum- 
berland river in southern Kentucky has been found, so far as 
can learn, in locations of similar disturbance. 
But there is another and very important class of facts to be 
noticed in connection with the subject of the geology of oil. 
We find in many parts of the country a very marked tendency 
in the oil to accumulate in certain geological horizons. The 
stratigraphical position of most of the oil in southern Ohio (in 
the Coal-measures) is in a vertical range of about two hun 
feet of rocks lying. below the horizon of the Pomeroy coal seam 
This is true in Meigs, Athens, Morgan, Noble and ashington 
counties. There are some exceptions to this rule, but they are 
On Big Sandy river in Kentucky, the conglomerate below 
the coal is the “oil rock.’’ In Scioto and Pike counties in Ohio 
there is a well marked horizon of oil springs in the Waverly 
sandstone, within twenty feet of its line of junction with the 
underlying black shale. At Mecca, in Trumbull Co., O., there 
is a similar and well-defined “oil rock.” But the most notable 
fact of this kind is observed in Venango Co., Penn., where, on 
Oil creek, Cherry run, and Pit-hole, the oil is chiefly obtained 
in the fissures of the “third sand-rock.” This rock’ is reached 
at a depth of from eight hundred to a thousand feet below the 
of the Coal-measures. Coal is mined in the hills adjacent 
to Pit-hole creek. No oil, so far as I could learn when investi- 
gating that region, has been obtained in the arenaceous shales 
below the third sand-rock, although a few very deep oe 
been sunk. No sand- rock was found below the thi 
is found in the third sand-rock, not because it is the third, = = 
because it is the lowest, and as such has intercepted the oil 
upward ascent, I should here remark that the third san 
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