Page 210 - 1915, Springs of CA.

194 SPRINGS OF CALIFORNIA.
ably sulphureted, salty water.1 The pool is used as a drinking basin,
and a pipe leads from it to a heating tank a few yards away and thence
to a small bathhouse. Besides its use by campers for bathing, the
water has been bottled and sold locally.
In two or three places a few hundred yards farther upstream there
are small lime-carbonate deposits where carbonated water evidently
issued at a former period. The second spring, which is called the
Arsenic Spring, flows from a small pit dug in a grassy seepage area
on the hillside about 175 yards northwest of the Main Spring. It
yields perhaps one-half gallon a minute of salty magnesic water and
has been used for drinking.
A small amount of serpentine is exposed near the Arsenic Spring
and probably furnishes the magnesic contents of both springs.
Well-bedded sandstones and shales that continue up the canyon
beyond the spring probably furnish the other mineral constituents.
Cemented gravels belonging to the beds described by Becker 2 as the
Cache Lake beds, of late Pliocene age, extend up the canyon approxi-
mately to the springs. The springs apparently issue at the eastern
limit of the gravels, though conclusive evidence of this was not seen.

OIL SPRING (COLUSA 8).
Prominent deposits of lime carbonate have been formed on the
steep hillside that borders the western side of Bear Valley, about 1J
miles north of Wilbur Hot Springs (Colusa 9, p. 99). These deposits
extend for about one-quarter of a mile along the hillside and 200 to
300 feet above Bear Creek. At three or four places there are seepages
of salty, carbonated water, but the main flow is at the northern and
largest deposit. Here a spring that is locally called the Oil Spring
yields about 2 gallons a minute of water, 76° in temperature, that
tastes salty and disagreeably of petroleum. A number of years ago
a shed was built over the spring, a collecting tank for the oil was
placed near by, and a pipe line was laid to two large storage tanks in
a shed beside the creek. In 1910 these improvements still remained,
but the attempt to collect oil in commercial quantity from the spring
had proved unsuccessful. A well that was drilled for oil a few miles
north of the spring was also unsuccessful in obtaining a supply.
The spring and associated seepages issue from shales and sand-
stones that here border Bear Valley and extend eastward to Sacra-
mento Valley. These sediments are relatively unaltered, compared
with the sediments of the Franciscan formation, but a portion of
them may belong to the Knoxville formation (Lower Cretaceous).

1 An analysis of this water, indicating a mineral content of about 1,100 parts per million, with rather
low sodium and magnesium and unusually high lithium, has probably been incorrectly reported.
2 Becker, G. F., Geology of the quicksilver deposits of the Pacific slope: U. S. Geol. Survey Mon. 13, pp.
219-221, 1888.