48 OIL DISTRICTS OF SOUTHERN CALIFORNIA. 
of northerly dip has been altered by the crushing that it has under¬ 
gone in proximity to the fault. 
The Modelo shale of Sulphur Mountain and the valleys north and 
south is continued east of Santa Paula Canyon in the foothills of the 
Santa Paula Ridge and San Cayetano Mountain; finally, by the con¬ 
vergence of faults, wedging out between the Fernando sediments of 
the foothills and the Topatopa formation of the mountain. 
The general strike of the formations north of the Modelo is N. 65° 
W., the dip being 40°-70° N. Adjacent to the Silver Thread fault line 
the Modelo also strikes N. 65° W. parallel with the break, but along 
Sisar Creek the direction changes to nearly east and west, while south 
of Sulphur Mountain it is N. 60°-70° E. Immediately south of the 
main fracture the shale of this formation dips to the north, toward the 
plane of displacement, the axis of the adjacent anticline lying perhaps 
200 or 300 yards farther south. 
Although the prevailing dip near the Silver Thread fault is north¬ 
ward, the strata, nevertheless, present more or less irregularity of 
occurrence, the appearance suggesting a fragmental condition of the 
formations. This may readily be the case along a fracture of such 
proportions, the amount of displacement being hardly less than 5,000 
or 6,000 feet. 
OIL WELLS. 
The oil wells of this district all lie immediately north of the Silver 
Thread fault, which separates the Modelo shale and the Sespe red 
beds. They pierce the red beds, and a few wells in their upper por¬ 
tions pass through the more southerly members of the older but over- 
lying rusty beds that carry Eocene fossils. None of the wells is distant 
more than 200 or 300 feet from the plane of fracture, while one or two 
are especially close to it, appearing, indeed, to have been sunk in 
crushed rock of the Modelo formation; however, in view of the uncer¬ 
tainty as to the dip of the fault plane it may be that they pass at slight 
depth from the fragmental Modelo into the more solid strata of the 
older formations north of the fault. 
The maximum depth attained is a little over 1,000 feet. The wells 
are all small, 12 barrels per day being the largest individual yield at 
the present time. The gravity of the oil varies somewhat from well to 
well, but the average is approximately 19° B. The color of the oil is 
green. The only flowing wells are those of the Ojai Company, which 
lie west of the others, with their collars at a considerably lower eleva¬ 
tion; they are also very shallow and are, moreover, located directly 
in the line of seepage of the region. 
