164 
OIL DISTRICTS OF SOUTHERN CALIFORNIA. 
interbedded with minor amounts of arenaceous shale. The anticline, 
if such it be, is also exposed at the corner of Bernardo and Adobe 
streets, where the dip ranges from 75° N. through perpendicular to 
40° or 50° S. Here, again, the surface evidence indicates an overturn 
while the well logs suggest a sharp anticline. The productive wells 
are found, with few exceptions, on the south side of this line of dis¬ 
turbance. 
As before mentioned, there also appears to be a fault a short dis¬ 
tance south of this anticlinal axis, but what relation, if any, it bears 
to the productiveness of the oil sands is at present unknown. The 
fault which throws the oil-bearing beds in the field down against the 
older Puente strata of the Elysian Park anticline is apparently closed 
so far as escape of the oil is concerned, for no indications of oil or 
asphaltum have yet been discovered along its trace. The sealing of 
the north end of the truncated oil sands by the impervious material 
of this fault zone may account in a measure for the retention of the oil. 
In the vicinity of Chavez Ravine, and immediately north of the main 
eaist-west fault, which limits the productive territory of the eastern 
field on the north, the strata strike N. 80° W., with dips varying 
from 20° to 30°. A disturbance affects the beds, however, at the 
corner of Elysian Park avenue and Innes street, just north of Res¬ 
ervoir Hill, where they dip in a northwesterly direction, although the 
dips all around this point are uniformly toward the south or southwest. 
The territory between the eastern and central fields is considerably 
broken up and, as reported by the drillers, contains much water and 
little oil. This condition is doubtless due to a zone of disturbance 
which branches off from or is a continuation of the fault at the corner 
of Sunset boulevard and Sutherland street, and which extends from 
this point in a general south-southeasterly direction past the corner of 
Sunset boulevard and Innes street toward the Sisters’ Hospital. The 
character of this line of disturbance has not been determined, but it 
appears quite probable that it is a fault zone, with the downthrow on 
the east. 
DEVELOPMENT. 
The first well drilled in the eastern field was sunk at the corner of 
Adobe and College streets in November, 1896. From the time this 
well was found to be successful until the latter part of 1897 develop¬ 
ment v r ent on rapidly until nearly the wdiole of the productive territory 
was exploited. Since 1897 few 7 wells have been put down, while a 
number of those which at one time produced considerable quantities 
of oil have become exhausted and have been abandoned. There are 
at present (February, 1906) 270 wells in the field, of which 211 are 
pumping and 59 are either not pumping or are abandoned. The wells 
vary in depth from 500 to more than 1,200 feet and yield from 1 to 
12 barrels of oil per day. Some of the wells are said to have yielded 
