156 
OTL DISTRICTS OF SOUTHERN CALIFORNIA. 
cline are exhibited in the Puente shale and sandstone to the north¬ 
east of the major flexure. Many of these latter folds are very sharp, 
dips of 60° or more being the rule. They are doubtless the result of 
tangential compressive stresses. South of Eastlake Park are vio¬ 
lently disturbed beds whose structure is rather uncertain. Appar¬ 
ently, however, they lie in a closely compressed anticline, with axis 
trending in a general east-west direction along a line making a com¬ 
pound curve. This fold affects beds of probable Fernando age. The 
apparent analogy of this anticline, if such it be, to those in certain oil- 
producing areas of southern California leads to the inference that oil 
may be confined beneath it. However, those wells which have been 
put down east of Los Angeles River have not proved successful. 
Southwest of the Elysian Park anticline is a syncline accompanied 
by a zone of faults. This flexure extends from the region southeast 
of Prospect Park in a broad northeasterly convex curve to the 
vicinity of the Sisters’ Hospital on Bellevue avenue and separates the 
steeply dipping shale on the northeast from the softer flatter beds of 
the rolling-hill country southwest of the line of disturbance. (See 
PI. XX, sec. E-F.) The southern extension of this syncline is trace¬ 
able as a fault from the corner of Sunset boulevard and Sutherland 
street to a point just south of Innes street and thence southeastward 
toward the Sisters’ Hospital, and is doubtless responsible for the breaks 
in the productive oil belt which occur in the vicinity of the hospital. 
The most prominent structural feature belonging to the east-west 
Pleistocene system is the fault zone extending along the southern face 
of the Santa Monica Mountains from Los Angeles River at least as 
far as Hollywood and probably much farther west. (See PI. XX, 
sec. C-D.) This fault zone has been largely instrumental in the for¬ 
mation of the range. It allows the upper Puente shale to come into 
contact with the granite, from which it is ordinarily separated by at 
least 2,000 feet of conglomerate and sandstone. Associated with this 
profound displacement are minor parallel faults in a zone which is 
characterized by man}" fractures and much distortion of the strata. 
STRUCTURE OF THE OIL BELT. 
The Los Angeles oil field is developed in strata at the top of the 
Puente formation on the southern limb of the great Elysian Park 
anticline. (See PI. XX, sec. E-F.) The trend of the productive 
belt, however, instead of conforming to the axis of the main fold 
follows the strike of the formations on the south side of a divergent 
subordinate fold and hence has assumed a direction closely approxi¬ 
mating east and west. The axis of the subordinate fold is traceable 
from a point near the corner of Lake Shore avenue and Temple street 
south of Echo Lake, westward to a point north of Westlake Park 
