LOS ANGELES DISTRICT: WESTERN FIELD. 
173 
GEOLOGY. 
Superficial Pleistocene deposits cover a large part of the western 
field, but from the examination of exposures along the ravines in its 
eastern part and from a study of the well logs it is known that the 
formations underlying it are the same as those exposed in the eastern 
and central fields. These are the lower Puente sandstones, the 
Puente shale and thin-bedded sandstone, the Fernando sandstone, 
and the Pleistocene gravel, sand, and clay. 
The most prominent bed exposed is the coarse sandstone which 
lies between the bands of hard, white, thin-bedded shale at the top 
of the Puente formation. Exposures of this sandstone may be 
traced from the hill one-half mile north of Westlake Park to the bend 
in the Hollywood and Cahuenga Valley Railroad at the corner of 
Western avenue and Temple road. The exposures one-half mile 
north of Westlake Park show a medium to coarse or rather gritty 
sandstone, with colors varying from light yellow and brown to choco¬ 
late, gray, and dark brown. The beds are considerably disturbed, 
being near the point of change of strike from N. 80° W. to N. 65°-70°* 
N. West of this locality, toward the Baptist College, the sandstone 
outcrops along the face of the hill east of Occidental boulevard. 
Still farther west, at the corner of Commonwealth avenue and Geneva 
street, the sandstone dips 20° S. 20° W. and is interbedded toward 
the top with some thin layers of hard siliceous shale. Immediately 
southwest of the Baptist College the same sandstone, highly impreg¬ 
nated with oil, in layers from 12 to 36 inches thick, has a dip of 
20° S. At this point the sandstone is coarse and chocolate colored, 
and is interbedded with 1- to 12-inch layers of chocolate-colored 
shale, which contains large quantities of carbonaceous matter and 
some sulphur. 
Immediatel} 7 ' north of the Baptist College are some exposures of 
white thin-bedded shale, interbedded with softer, darker-colored 
shale which dips toward the south, under the coarse sandstone. This 
shale continues toward the northwest and is exposed in a much crum¬ 
pled condition on First street about one block east of Vermont avenue. 
It also occurs in a small ravine near the junction of Rosedale avenue 
and the Hollywood and Cahuenga Valley Railroad. The last good 
exposure is found on Western avenue, just north of Temple road. In¬ 
terbedded in the shale about 300 feet stratigraphically below the main 
layer of coarse sandstone, is a band of somewhat similar sandstone 
which appears to be the principal productive bed in the western field. 
This lower sand is well shown in a cut on the Hollywood and Cahuenga 
Valley Railroad at Vermont avenue. The dip here is 10° due west. 
The sandstone looks very much like that exposed on Sunset boulevard 
and has similar large ellipsoidal concretions. It does not appear to 
