The herald., 1896-04-23

Is quite possible that wells yielding
small amounts OF oil might be obtained
in that direction.
TO the eastward the outlook is little
better. At first sight the steep dip Of
the formation, as seen at the corner of
Beaudry and Bellevue avenue is very
disheartening, for the continuation of
SO steep dip would restrict the field
to very thin oil line. The rock expos
ures on Bartlett street, near Pearl, show
dip of little west of south at an angle
of about 20 degrees, which leads to the
conclusion that the steepness of the dip
at Beaudry and Bellevue avenue Is but
local. There is, however, a fault on
Bellevue and Centennial street which
might cause trouble.
AS is well known, several enterprtsing
citizens have drilled wells in an endeav-
or to find other oil lands in the vicinity
of Los Angeles, but without success. In
most instances, however, the strata they
penetrated showed small quantities of
oil.
The great obstacle to geological work
around Los Angeles is the few rock
exposures, owing to the sue ire being
covered with earth and IN many places
with houses. Between Los -AnsscleS and
the ocean there are many points where
bituminous matter eXudes from the sur
face of the ground, but no good expos
ures of rock can be found without going
far back in the hills. On the seashore
north of Santa Monica there is an ex-
cellent opportunity for observing the re-
markable series of rocks. Along the
shoreline a soft sandy formation, prob
ably of Quarternary age, rests noncon-
formally on sandy and shaly strata,
containing Pliocene fossils. This Plio-
Gene formation Is for the most part thin
bedded. In the lower portion of 1t there
are bituminous strata and numerous
thin strata of impure limestone. The
upper portion of it shows much mica
eous material and infusorial earth.
In this paper have omitted the ques-
tion as to whether the deposit of petro-
leum at Second street park is primary
or secondary deposit. A primary de-
posit, as explained when ! last had the
honor of addressing you, is deposit
of petroleum contained in the stratum
of rock in which it was formed, Such
a deposit, although 1t may vary in rich
ness, can be confidently traced along
the strike of the formation, 1t conforms
to the general photographic contour of
any conformable rocks which may en-
close it.
A secondary deposit of petroleum is
supplied by petroleum, which has wan
dered from it's original source and finds
q resting place in any porus strata it
may reach.
TO elucidate this matter | have here
in diagram three an illustration from one
of our standard works on petroleum,
which has been slightly modified so as
to express the matter in one picture.
The green stratum at the bottom,
A. b., is a primary deposit, |. e.. STRAIT
um in which the petroleum originated.
Providing there are sufficient rock ex-
posures, by suitable geological observa-
tions it can be traced wherever it eX-
tends.
A neglect of such observations, as in
the case of the we'll marked F, will result
in failure.
The stratum at the top. which is mark
ed c. D., and is cut through by a ravine,
has been saturated with petroleum
which has come up through a flssure
from the primary deposit below. The
blue stratum C. ID. is a secondary de-
airy deposits 1 am not sure that this is
rock for some distance from this fis-
sure, but unless fed by other fissures
it would become poorer and poorer, and
at last cease to be petroleum bearing
In most parts of the world the primary
deposits consist of lighter oil and con-
tain more gas than Is the case in second
ary deposits. lam not sure that this is
always the case in California. owing to
the broken nature of the rocky forma-
tions.
The oil-bearing stratum at Second
street park has not been traced far
enough to determine on stratagraphic
grounds whether it is primary or sec
ondary formation.