The Potter journal. [volume] (Coudersport, Pa.) 1857-1872, 1861-02-21
From the PHtSjurg Gazette
Rock CEl--Efs Geological Form
alton.

2cek CIi--Efs Ge01og5cal Form
The recent important developments
made in Western Pennsylvania, Ohio and
some parts of Virginia and Kentucky,
respecting the deposit of Petroleum or
Rock Oil in certain strata Of the earth,
have already been carried far enough to
afford some date toward the solution Of
the problem Of It's range and distribution,
if not of its source The extensive in
terest which has been ELECTED from the
fact of large quantities of oil having been
found in some places, by boring in the
earth, if nothing more, should demand
for the question the most rational consid-
Grafton.
When the first we'll was found near Tt
tusvi,le, Crawford county, Pa, it was nat
urally enough supposed that that imme-
diate vicinity and the valley of Oil Greek,
where it made its appearance on the sur
face, alone contained this strange deposit
of oil; since, however it has has beer
later found in widely separated districts,
it is wildly believed by many that it ev-
erywhere exists at certain depth in the
earth, But like all other materials yalu-
able to man, stored up in the crust of the
earth, the oil must necessarily be subject
in its range to conditions of geological
structure, and, since it is fluid, also in
some degree, geographical elevations and
depressions,
1t is proved by sufficient number of
facts that the oil belongs to one and the
same geological vel, viz: the Chomung,
and Portage Group Of the New York Ge-
ologists, or the Vergcnt strata according
to the nomenclature Of Prof II. d. Rog-
ers in his final report on the Geology Of
Pennsylvania. This fact was mentioned
in report on this subject read before
the American Association of Science, at
its last annual meeting. In a few places,
however, where there are anticlinal frsc-
lures, or where the strata to which it nat
urally belongs is suak deep under super
imposed formation, the oil rises In assures,
as it is borne by water, or forced by gas,
into the everything strata. This is the
case in some parts Of Virginia and in the
deep valley of the Ohio River.
But it is rendered doubtful by many
considerations whether the Vergcnt rocks
are wholly or even in part, the original
source of oil. la many places where the
underlying slate, (the Cadeut formation
of Prof. Rogers emerging from under
the Vergent sandstone exposes higher
geographical surface, as in the high range
of country between the waters Of Lake
Erie aud the Allegheny River, small
quantities of petroleum are found in quar-
ries and natural caverns, aud an abund-
ance of Carburetted hydrogen gas Is emit
ted, as at Fredonia, New York and many
other places. Prof Rogers describes the
slaty deposit as :" almost everywhere more
or less bitunlinous, yielding petroleum on
and emitting naturally not
only this fluid, but much carburetted hy-
drogen or coal gas" which with many
other facts, makes it highly probable that
this bituminous slate is, at least in part,
the original source OF oil, which accumu
lates in veins in the troughs Of the over
lying Vergent layers. For, from its na-
ture, subterranean fuid, in seeking al
level, must circulate in the direction of
the lowest depressions of the strata that
hold it, and, if lighter than water, or ac-
by gaseous substances, where
the dip of the rocks is greater than the
geographical fall, would also be borne up
ward. The entire Vergent strata, con-
sisting of shale and sandstone, have, in
Western Pennsylvania. whore they every
where undeYie all the coal measures, a
thickness of from one to two thousand
feet; and if the foregoing suppositions
are well founded, may contain more or less
oil throughout the whole depth. But
whatsoever may be its source, the accu-
of the oil must necessariallY be |
largely controlled by the geological ele-
vations and depressions of the strata in
which it circulates.