50 OIL DISTRICTS OF SOUTHERN CALIFORNIA. 
more earthy than many of the Modelo beds. Still farther south are 
Fernando sandstone and conglomerate, which, with shale and clay, 
extend well out beneath the sloping foothills of the range. The strata 
in the fault zone and adjacent to it on the south have a northerly dip, 
varying from 80° in the sandstone and conglomerate just south of 
Bear Canyon and the well area to 50° in the well areg itself and to 30° 
in the escarpment of Santa Paula Ridge and San Cayatano Mountain. 
The throw of the fault plane separating the Modelo and the Topatopa 
formations amounts, doubtless, to many thousand feet. A second 
fault probably exists in the interval between the Modelo siliceous shale 
and the Fernando sandstone and conglomerate south of Bear Can¬ 
yon and at the head of Mud Gulch, the intervening brown shale, 
which is earthy and stained with bitumen, belonging, in the writer’s 
belief, to the older formation. The strata south of the second fault 
are probably overturned, and only at a depth of 1,000 or 2,000 feet 
assume their regular dip to the south. This fault is probably the 
easterly extension of that existing along the southern base of Sul¬ 
phur Mountain, since its trend and that of the adjacent strata is 
N. 65°-80° E., in conformity with the strikes in the latter region. 
The northern fault is doubtless the extension of the fault passing 
north of Sulphur Mountain, its trend and that of the lines of strati¬ 
fication adjacent being N. 65°-80° W. The extent of throw along 
the southern fault is undetermined and may vary from 500 to 1,500 
feet. These two faults come together about 5 miles east of Santa 
Paula Creek, in the vicinity of the Empire wells, and east of this 
point only a single fracture is present. 
OIL WELLS. 
The wells of this field are confined chiefly to the brown shale and 
range in depth from a few hundred to nearly 2,000 feet. Sandy beds 
undoubtedly occur; but in the main the strata are blue, brown, and 
black shale, with occasional harder layers, known to the drillers as 
“hard shells.’-’ The oil is found in the coarser sediments. The 
Empire wells, in the eastern part of the field, show traces of the Fer¬ 
nando sandstone and conglomerate, from which, doubtless, they draw 
a portion of their oil, the remainder coming from the underlying 
Modelo formation. Some of the wells of this field are reported to 
have started at 200 barrels or more, the yield after a short time falling 
off until it is now between 5 and 20 barrels. The oil is light, its 
gravity being 35° B., and of greenish color, resembling in a measure 
that from the same formation in the Puente Hills. 
The companies operating east of Santa Paula Creek are the O’Hara, 
the Chicago Crude, the Paxton Gold Bond, the Pure, the Hartford, 
the Cuniff, and the Empire. 
