194 
OIL DISTRICTS OF SOUTHERN CALIFORNIA. 
between the Catholic Cemetery and the Westlake Park region, the 
southern limb of the flexure dips normally at angles varying from 30° 
to 80°, while to the west, along that portion having a northwesterly 
trend, the dips flatten to 20° or 25°. The Salt Lake oil field is located 
on the northwestern flank of a minor, but probably somewhat complex 
fold or fault, or both, developed on the comparatively low-dipping 
southwestern limb of the major flexure just described. The dip of 
this flank of the local fold is reflected in a general way by the surface 
slope, which descends gently from the region of the present productive 
field northwestward toward Sherman. This slope probably indicates 
a Pleistocene or post-Pleistocene orogenic movement similar to but 
apparently of much less magnitude than that which produced the 
original flexure. 
o • 
The exact nature of the local flexure is not known, but it is probably 
an anticline, more or less complicated by faults near the apex. Its 
axis extends in a general northeast-southwest direction. The logs 
of certain wells located southeast of the lagoon appear to indicate the 
presence of a minor anticline developed just south of the main flexure 
and separated from it by a fault. Still other evidence suggests a 
local dome-shaped structure, or quaquaversal, having its summit in 
the region of the lagoon. The length of the Salt Lake flexure is 
unknown, although the available data seem to indicate its extension 
at least from a point near the'center of the 'SE. I sec 15, T. 1 S., R. 14 
W ., as far as the lagoon in the SW. \ sec. 21. Whether or not it con¬ 
tinues farther to the southwest is problematical. 
The large accumulations of brea in the immediate vicinity of the 
lagoon and to the north and northwest of it, in addition to the con¬ 
stantly exuding oil and escaping gas over the same area, indicate some 
sort of a profound local disturbance or fracture in the underlying beds. 
If this disturbance has an extensive longitudinal dimension in a 
northwesterlv direction from the lagoon, as some of the evidence sug- 
gests, then it may possibly cut off the Salt Lake flexure from a south¬ 
westerly extension beyond the lagoon. II, however, the structure in 
the vicinity of the lagoon is a local bulge or dome in the underlying 
beds it is quite likely that the Salt Lake flexure may have a consider¬ 
able southwestern prolongation. 
The contour lines on the map of the Los Angeles field (PL XIX) 
and the section shown in PI. XX, A-B, and in fig. 17 illustrate the 
writer’s ideas concerning the local folds. From the map it will be 
seen that the strike of the oil sand probably swings around from a 
nearly east-west line in the region north of the lagoon to a direction 
slightly west of north in the NE. J sec. 21. The dip of the sand in the 
region about the center of sec. 21 does not appear to be much more 
than 10° or 15°, but it increases rapidly in steepness toward the 
southeast up the rise and probably also toward the northwest, or 
down the dip. 
