Page 80 - 1915, Springs of CA.

76 SPRINGS OP CALIFORNIA.
The Main Sulphur Spring has a flow of primary alkaline saline
water in which secondary alkalinity and tertiary alkalinity are minor
properties. The three analyses of this spring indicate a gradual change
in character toward secondary alkalinity at the expense of primary
salinity. The Mud Bath and Sand springs are essentially primary
saline and are similar both in character and concentration. The
White Sulphur Spring is distinguished from the others by a higher
secondary salinity and iarge relative proportion of magnesium.
Anderson's analyses of the Soda and Iron springs show them to yield
primary saline waters in which secondary alkalinity is a prominent
and primary alkalinity a minor property. The Jaffa and Hogland
analysis of Soda Spring represents a water of rather complex character,
such as would be obtained by adding calcium sulphate to the water
represented by Anderson's analysis. This may be accounted for by
a change in the character of the water, but it is not unlikely that dif-
ferent springs were sampled for the two analyses.
A fault is mapped as extending southward along Salinas Valley
nearly to Paso Robles, and two other faults have been traced in the
hills to the west. Such broken structure may also exist at Paso Robles
and give rise to the springs, but the warm water that issues naturally,
and is also obtained from deep wells here, may be of artesian origin
and be drawn from the deep alluvium.

SANTA YSABEL SPRINGS (SAN LTTIS OBISPO 3).
About 4 miles southeast of Paso Robles a large volume of warm
sulphureted water rises in a ravine on the eastern side of Salinas
Valley. In the late eighties a resort was started here,.but the plans
were not carried out, and in 1908 there was only a small private
bathhouse at the springs. One main spring rises beneath the bath-
house and discharges about 150 gallons a minute of water 94° in
temperature. At the northeast corner of the bathhouse another
warm spring of slight yield rises in a concrete basin. The water
flows northward half a mile to a storage reservoir or artificial lake,
and is used for irrigation.
Small incrustations of gypsum form on stones over which the
water flows near its source, and a small amount of acid salt is also
deposited. The following is an analysis of water from the main
spring. An analysis of water from the spring at the northeast corner
of the bathhouse shows that it is practically the same as that of the
main spring.