Page 242 - 1915, Springs of CA.

224 SPRINGS OF CALIFORNIA.

CAVE SPRING (SISEIYOU 25).
Cave Spring is near the eastern edge of Sacramento River and
about one-half *mile north of Upper Soda Spring. It issues from a
crevice in the rock at the base of a 25-foot cliff of dark-colored lava,
beneath which is the small cave from which the spring takes its
name. It has been used only as a drinking spring. Like Upper
Soda Spring it is cool and moderately carbonated, but it apparently
contains more iron thdn the former, as it has deeply stained its
overflow channel.

TWIN SPRINGS (SISKIYOU 24).
About 200 yards north of Cave Spring two small carbonated
springs rise about 4 yards apart in joints of tile pipe. They are
known as Twin Springs, and, like Cave Spring, are used only for
drinking. The water deposits considerable iron, but it does not
seem to be highly mineralized. Like Upper Soda and Cave springs,
Twin Springs rise near the base of a low lava bank. The lava is
also exposed across the river to the south and northward upstream,
but on the western side of the canyon, opposite Twin and Cave
springs and for some distance above and below them, light-colored
dioritic rock is exposed.1 This material may have had some influ-
ence in furnishing a place of upward, escape for the carbonated water.

CASTLE CRAG SPRING (SHASTA 2).
Castle Crag Spring was formerly known as Lower Soda Spring and
also as Hibbs Soda Spring, but during recent years the property
has been improved as a resort under the name of Castle Crag
Farm, and the spring has come to be best known by the newer
name. It is situated at the base of a bank near the southern edge
of Soda Creek, 5 miles south of Dunsmuir and a mile east of Sacra-
mento River. A number of years ago a stone and concrete spring
house was built over the spring, and the water formerly overflowed
from a cement basin in its center. When the spring was visited,
however, the water stood at about the ground level in this basin
but rose vigorously in a small open pool 5 yards away, as if from a
break in the supply pipe. The water is strongly carbonated and
deposits considerable iron. It is said that it has never been placed
on the market but has been used only at the spring. The following
analysis shows that it is a strongly alkaline-saline water:
i This rock has been examined microscopically by E. S. Larsen, jr., and found to contain granular augite
and secondary hornblende, chlorite, biotite, calcite, and sericite.