Page 42 - 1915, Springs of CA.

40 SPRINGS OF CALIFORNIA.

The ravine in which these springs issue is steep, with narrow,
precipitous sides, and the rock exposed is largely a crushed gneiss.
Recent landslide patches within it also indicate the broken and dis-
turbed character of this area and furnish local evidence that the
thermal character of the springs is due to crushing and slipping of the
rocks.
PILARES HOT SPRING (RIVERSIDE 7).
In the channel of San Jacinto Kiver, about 6 miles west of the base
of the San Jacinto Range, warm water rises and forms a tule area
several acres in extent. The water was formerly piped to a bath-
house on the higher land, but in 1910 a hut among the tules formed
the local bathing place. Though the abnormal temperature of this
water may be due in part to leakage of deep-seated hot water upward
through the San Jacinto fault into the alluvium of the valley, it is
more probable that a buried spur of a granitic ridge that here borders
the valley acts as a dam and forces alluvial water to the surface from
a depth sufficient to account for its temperature. A well that was
drilled a couple of hundred yards west of the spring obtained a warm
artesian flow.
PALM SPRINGS (RIVERSIDE 11).
At Palm Springs, at the southern base of San Jacinto Peak, a rise
of thermal water tends to confirm the topographic evidence that
faulting has taken place in this vicinity. The water, which has a
temperature of about 100°, is used for bathing, and there is a small
health resort here on the edge of the desert. These are the same
springs that were formerly known as Aguas Calientes (hot waters),
and the following partial analysis of the water was early made:

Analysis of water from Palm Springs, Riverside County, Cal.
[Analyst, Oscar Loew. Wheeler report (1876). Constituents are in parts per million.)
38° C. (100° F.)
Properties of reaction:
77
0
0
23
Trace.
?
By Reacting
Constituents.
weight. values.
158 6.87
Lithium (Li)...... ................................................................. Trace. Trace.
Trace. Trace.
Trace. Trace.
Sulphate (SOi)... ....... ............................................................ Trace. Trace.
Chloride (Cl)... ................... .................................................. 188 5.30
47 1.57
Silica (SiOi). ....................................................................... Trace. Trace.
393
Trace. Trace.