The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1910-04-21
MANY THEORIES
TO ACCOUNT
FOR PETROLEUM
Folding Strata Cause Ii TO
Appear in Spots Below
Surface
Traced by Some to Vegetable
Source, by Others to AMI
NAL Origin
cooper Explains His Views as
TO Its Presence in the
Earth

~NfNA OF ITO uSanCS of feet,
~ mere II is beyond the deepest well and
p others these strata have been brought
2eaF the surface by the folding Of the
rocks.
oIaD> OF MANY MILES
ne stretches or fields in which pay
eng wells occur in this state are par
sLael 70 the axes Of folds or to faulting
l5fles- The breadth Of the stretch or
-s-=id depends largely on the angle OF
II D Of the oil stratum and extends at
hest only small distance down the
? fold or fault tilted formation. The lat
: fral extent is limited by the outcrop or
.:by 2 fault OF by being brought too close
70 the axis OF the fold. The other ex-
'trremity is limited by the dip Of the
formation.
In the study OF the forma ton in
which oil is found il is necessary to
deal with the different types OF folds
~ the earth's crust and find their par
ocular characteristics for each district
j Is known that in some parts OF the
Norfd the earth folds are many miles in
breadth. In California il has been
round that the folded strata are mar
@tow and small particularly in the Coast
-lsange mountains.
+ The small folds are a great aid in
:,.iet erminins the geology Of the fields
and study Of them has ena bled drill
-ire TO be done intelligentIy.
in dealing with the earth lorna ton
II IS well TO mention the different folds
Rnd how the oil strata are affected by
tnen- In the geological classificat ton
there are principally four kinds OF
strata formation-the upright fold. in
which the strata slope away al equal
engles from the axis. the inclined fold,
IN which the strata OF one side slope
& way from the axis at 4 greater angle
than the strata Of the other side: the
overturned fold. in which the curve OF
IT, strata nearly laps itself; and, last
the fanshaped field, where the fold
't- The strata dips backward toward the
Skis Of the anticline.
WHERE OIL Il FOUND
. Lewis r. Aubury. state mineral oCist.
"a IN explaining the geology Of the fields,
sums Up the proposition briefly as fol-
lows;
~The granite core Of the Sierra Ne
. yada forms the backbone Of the state
and carries on its TANKS narrow ex-
posures Of pre-Cretaceous strata. run
ming far back as DevOnian usually
. much altered and Overlaid on the west
bv tile Pleistocene formations OF the
o.. .
Coast range shows generally q core Of
@:igneous rock oYerlaid on both sides
: :5yIth Cretaceous and later formations.
a s the oil deposits in the central part
. of the state are principally found near
:.-..le foot Of the Coast range, wells here
!. penetrate formations Of Eocene 10 Pie
:. istocene age, largely shales. cIays and
saudstones. The oil wells OF Ventura
'-@ounry are partly located in q base
limestone Of EOcene age. partly in
shales Of later period. The OIL City
pool of Coalinga is in the TETON"
II is the belief Of experts that the
formation Of folds and rock discov-
cred in the hills does not necessarily
terminate there. but may extend be
meath the slluvium Of the valleys Al
though the well seen far out on the
b. plains in the San joaquin valley is usu-
HIly characterized by the unIovelv ex-
i. preston wildcat" there is no doubt
shat the oil lines discovered in the hills
may be followed into the valley where
The. folds Of rock lie under q deep cover
:of slluvium.
ORIGIN OF PETROLEUM
= Concerning the origin or the oil fl
self there are many conflicting theo-
ries. There are three principal sumo
sitions --arthy Of mention: first. that
petroleum was formed by the cherniesl
- combination Of Inorganic matter So,
ond. by chemical change. with or with
out natural distillation OF animal mat
ter and. third. by chemical change with
or without natural distillation OF vege-
table matter.
CoOPER'S THEORY
The oil formation was recentlv OK
- aimed by A :. Cooper. former state
mineralogist, ia simple terms He said:
1.-THE coast ranges Of California CON
sist Of over 5000 miles Of antfcljnaI
ridges extending from the northern 70
the southern boundaries Of the state
These auticlines usually have A north
> west and southeast trend. Sometimes
I've or more anticlines run crudely par
elei with each other.
AT the time Of their deposition he
meath the sea, the sandstone and shale
strata Of the coast ranges were approx
fmately horizontal, the anticiines form
ing the chains Of mountains and hills
nf the coast ranges being only waves
of upheavaI caused by the compression
Of neither molten rocks through the
contraction OF the globe through cool
ing.
The nearly vertical assures made in
the strata by these waves Of upheaval
allowed the vapors OF petroleum oil.
natural gas and sulpEureted hydrogen.
formed by the distillation of carbo-
d naceous and bituminous substances, TO
come up from a depth Of 10000 feet
or more and condense in cooler strata.
snder a cover Of close textured rocks
900 or more feet in thickness, where
the drillers tapped them in the form
Of oil or gas But where the bend
ing Of the strata was acute the assures
. extended all the way up 20 the surface
the oil and the gas came up. the oil
forming impure beds Of asphaltum, and
the gas went off in the air as fast as II
was made
;upIifted 70 e great height were badly
l~sken. so that they were washed away,
kxDosing the burned rocks IN which the
oil and gas were distilled These up
I lifts produced. earthquakes Of greater or
! less intensity, and only a small area
of these anticlines has been rightly