76 
OIL DISTRICTS OF SOUTHERN CALIFORNIA. 
OIL FIELDS SOUTH OF THE SANTA CLARA. 
GENERAL STATEMENT. 
The oil fields south of Santa Clara River involve an area having an 
east-west length of 29 miles and a width of from one-half mile to 4 miles. 
For convenience of discussion the territory is divided into foui fields, 
which lie at varying intervals along the front of Oak Ridge and the 
Santa Susana Mountains, none being yet developed on the slopes of 
South Mountain. Enumerated from west to east they are the Bards- 
dale and the Torrey-Eureka-Tapo fields, on the north flank of Oak 
Ridge; the Pico field, comprising Pico, Dewitt, Towsley, Wiley, 
Rice, and East canyons, along the Santa Susana Mountains; and the 
Elsmere field, containing the Elsmere and Placenta wells, on the 
spurs of the San Gabriel Range. (See PI. V, p. 36.) 
The fields are developed along the axes of the Oak Ridge, Torrey, 
Eureka-Tapo, Pico, and Elsmere anticlines. The Placerita wells are 
quite independent of the others and are located on the northward¬ 
dipping schists of the San Gabriel Range. The formations involved 
are the Sespe (Eocene); Vaqueros (lower Miocene);’and Fernando 
(largely Pliocene). All of these are productive. In addition the 
schists of the San Gabriel Range afford some oil. 
BARDSDALE FIELD. 
LOCATION. 
The Bardsdale field, as here described, includes South Mountain and 
Oak Ridge as far east as the vicinity of Chaffee Canyon. As all of 
the proved oil territory in the field lies north of the crest of the range 
the detailed descriptions will deal largely with the northern slopes. 
GEOLOGY AND STRUCTURE. 
The South Mountain-Oak Ridge anticline extends the entire length 
of the two ridges from which it receives its name. The axis is well 
down on the northwest slope of the mountains, in most places at a 
distance of less than half a mile from the edge of the Santa Clara 
Valley and locally but a few rods away. At the west the axis dis¬ 
appears beneath the valley filling a few miles from the end of South 
Mountain, leaving the extremity of this ridge wholly on the southern 
limb of the fold. At the east the anticline terminates abruptly 
against the northwest-southeast system of folds that sets in at Chaffee 
Canyon and continues thence eastward to Fernando Pass. 
The trend of the anticlinal axis varies in sweeping curves between 
N. 65° E. and east and west, displaying a certain degree of parallelism 
with the nearer strikes and with at least one structural curve—that on 
