16 SANTA MARIA OIL DISTRICT, CALIFORNIA. 
The Casmalia Hills include the group extending from the coast at 
Point Sal to Graciosa and Harris canyons and San Antonio Valley. 
The Solomon Hills lie between the Santa Maria Valley, Foxen 
Canyon, and the Los Alamos Valley, and between Divide and La 
Zac a Creek. 
The Purisima Hills lie between Lompoc, the Santa Rita Valley, and 
the Santa Ynez Valley on the south and the Los Alamos Valley on 
the north, and between Burton Mesa on the west and Alamo Pintado 
Creek on the east. 
The Santa Rita Hills lie between the Santa Ynez and Santa Rita 
valleys, extending from a point east of Lompoc nearly to the east 
edge of the Santa Rosa grant. 
The name San Antonio terrace is applied to the wide terraced region 
between Casmalia and the west end of the Los Alamos Valley. 
The Lompoc terrace is the plateau-like region of hills extending 
from the coast a distance'of about 5 miles east from Honda and the 
same distance southeast from Surf. 
In 1896 Id. W. Fairbanks used the names “Point Sal Ridge" for 
the axis of the hills between Mount Lospe and Point Sal, and “Lions 
Head” for a high, rugged mass of serpentine on the coast south of 
Point Sal. These features are so named here. 
RELIEF. 
GENERAL STATEMENT. 
The general character of the region covered by the Lompoc and 
Guadalupe quadrangles is that of a triangular hilly basin opening 
out toward the coast between two divergent ranges of mountains—the 
San Rafael Range in the northeast portion of the area and the Santa 
Ynez Range bordering it on the south. At the east edge of the area 
mapped these ranges are divided only by the valley of Santa Ynez 
River and the foothills north of it. Farther west the distance between 
them grows to 30 miles or more. The region situated in this angle is 
primarily a basin, owing its character and the details of its structure 
to its position between these ranges. This basin region, its struc¬ 
ture, and its oil deposits form the principal subjects of discussion in 
the present paper. 
Two lines of hills and three valleys occupy this trough between the 
two main ranges, radiating like the intermediate ribs of a fan between 
the lines that bound them. The more northerly of the two lines of 
hills is that of the Solomon and Casmalia hills, which are separated 
from the San Rafael Mountains by the wide valley of Santa Maria 
River. The more southerly is the range of the Purisima Hills, which 
is separated from the Santa Ynez Mountains by Santa Ynez River. 
These two lines of hills are themselves divided by Los Alamos Valley. 
