Page 113 - 1915, Springs of CA.

HOT SPRINGS. 107

The principal spring emerges at the northeast edge of the stream
in a natural rock basin at the foot of a small cliff, and yields perhaps
10 gallons a minute of water 105° in temperature. Considerable
gas, probably carbon dioxide, issues with the water. The latter is
mildly carbonated and is distinctly mineralized by salts of soda and
probably also of iron. The pool formed by this spring has long been
used for bathing and the water is locally considered efficacious in
the treatment of skin and blood diseases. About 20 yards southeast-
ward, upstream from the main spring, a smaller flow of similar water
issues from a seam in the rock at the creek edge, while 100 yards
upstream from the main spring there were, in 1910, three vigorously
bubbling, iron-stained pools that contained water 68° to 75° in tem-
perature. An area several yards in diameter in the creek channel
near by was also vigorously bubbling. It is said that there was
formerly a carbonated spring of considerable flow at this spot, but
that it was buried by a landslide a number of years ago and during
recent years has been in evidence chiefly by the large amount of gas
that escapes.
The springs are probably submerged during periods of high water,
but during the summer the stream carries only a few miner's inches,
and in some years may become dry for a short time.
The springs issue from siliceous rock similar in character to that at
^Etna Springs in Napa County (p. 156) and at other localities in the
State where quicksilver has been mined. A number of years ago
two tunnels were driven into the canyon side a short distance below
the Crabtree Springs, in search of quicksilver. The rock contains
noticeable amounts of cinnabar, but this mineral was not found in
paying quantity. The siliceous rock is closely associated with ser-
pentine, which is exposed for a few yards between the two groups of
springs on the northeast bank, and for a short distance on the south-
west side of the stream. There is also a cliff of the siliceous rock
opposite the main spring; but the principal material on the south-
west side of the canyon near the springs, and on the slopes both
above them and upstream from them, consists of altered shale and
sandstone. The serpentine of this locality appears to be the north-
ward continuation of a narrow belt that extends, with some branch-
ing or perhaps widening of the main zone, northward from Bartlett
Springs to this place, where it appears to be less than 100 yards wide.
The close relation of several carbonated springs to this belt of ser-
pentine is later referred to in the description of Royal Spring (Lake
6, p. 202). Like these others, the presence of Crabtree Springs and the
temperatures of their waters seem to be closely related to the serpen-
tine and the siliceous rock. The association of serpentine, siliceous
rock, and altered sediments with warm carbonated water at this place
is apparently similar to their association farther southward, at
Springs (Napa 2, p. 156).