Harrisburg telegraph. [volume] (Harrisburg, Pa.) 1879-1948, 1919-08-12
OIL SHALE DEFINED

What is oil shale? "A claims that.
in Colorado, it is compacted ooze of a
former inland marsh. b claims ii is
bituminized vegetable matter and Or
ganic remains of fossils from prehis-
toric times, evidence of which he has
seen in the mountains near De Beque,
Colorado. Is there more than one
variety, each of different formation?
II. Il. L.
New York"
Oil shale defines itself 1t is soft
lamnated or leaflike rock. formed by
the effects of pressure and heat from
deposits of clay and rock flour" and
containing more or less mineral OIL
derived from some of the materials
contained in the clay. In many regions
such as Southern California, the oil
would appear to have come principally
from the decomposition of diatoms
which are single-celled marine plants.
microscopic in size. which swarmed in
almost incredible numbers in the shall
low seas and waters formerly cover
ing regions where the shales are now
found.
In various parts of the world vast
deposits of diatom remains exist, some
times many square miles in area and
as much as fifty feet thick Ehrenberg
calculated that a single cubic inch of
such rock contained the remains of no
less than forty thousand million of
these ancient organisms.
But there are many varieties of oil
shale. depending for their precise COM
position upon the locality the geologi-
cal age, and the circumstances of their
deposition. Some of them date back
70
was earlier than the coal age" and
during which most of New York State,
except the Adirondacks, as well as
many of the central States toward the
West and Southwest, We're covered by
sea water. 1t is from these Devonian
deposits that most of the oil and gas
of Pennsylvania and West Virginia are
derived.
Even earlier than this, in the Or
dovician period. which goes within one
step of the very beginning of geologi-
cal history, oil rocks were formed, and
Professor W. ] Miller says: THE great
oil and gas field of Ohio and Indiana
derives its principal supply from the
Ordovician rocks, especially the Tren-
ton limestone. The oil and gas We're
formed by the decomposition of the
rich organic accumulation in the lime
stones"
In the Cretaceous and the Jurassic
periods. millions of years later. and
long after the coal age" which term
is conventionally limited to the Car
boniferous period, deposits of oil shale
were extensively formed, and it is
possible that the decomposition of the
abundant animal organisms of those
times (Which included the "age of the
great reptiles") may have added some
thing to the store of oily material in
the clays, although the diatoms and
similar minute marine plants continued
through all these ages. to flourish most
abundantly in the waters, and probably
constituted the principal source from
which the oil was formed. In Texas
and Louisiana the cruetaceous deposits
have been the principal source of oil
and gas, and they have served simi-
lar purpose in various places in the
Western United States.
Again, in the Tertiary, the last of
the great geologic periods before the
present. oil shales were laid down in
the form of clays at the bottom OF
shallow seas and other eXpanses OF
water. and notable among the tertiary
deposits furnishing large quantities oi
oil are those OF Southern California
| although there oil is also obtained
from jurassic rocks.
| So. you see there is, indeed, a great
! variety of oil shales. The business
man is more interested in the questions
of their locality, availability. produc.
/ tiveness, etc, while the philosophiC
thinker finds pleasure and instruction
in considering the manner of their for.
nation, and contemplating the immense
! lapses of time and the enormous ex.
, pednitures of life involved in their
/ history.
! For. if there had been no living
| things on the earth during all those
aeons of slow progress in the shaping