Page 212 - 1915, Springs of CA.

196 SPRINGS OF CALIFORNIA.

siliceous sandstone. Each spring yields one-half to 1 gallon a minute
of moderately carbonated water, 60° to 65° in temperature, and heavily
stains its overflow channel with iron. The water of the northern-
most spring tastes noticeably of salt. The position of the springs
near the northern border of the lava area is worthy of note and also
their occurrence near cold fresh-water springs (Lake 28, p. 358), which
are not common in this region.
DINSMORE SODA SPRING (LAKE 24).
A carbonated spring of seeping flow that issues on the Dinsmore
ranch, at the west edge of Wolf Creek, has long been protected by a
concrete curb and used for drinking. Its water is moderately car-
bonated and slightly salty but is pleasing in taste and is much used
during the summer. On the eastern side of the creek, about 300 yards
downstream from the main spring, a few seepages issue fronra small
deposit of lime carbonate on the steep bank. On the mountain side,
about 2J miles northward from Dinsmore's, there is a large carbonate
deposit that is evidently a spring deposit, but little or no water now
issues near it.
The rocks on the higher slopes north of Dinsmore's place consist
mainly of shales and coarser sediments, with areas of serpentine, but
near the spring the materials are siliceous, being apparently altered
shales and sandstones and some chert.
CARBONATED SPRING NEAR NORTHEAST SIDE OF CLEAR LAKE (LAKE 23).
In a ravine about half a mile east of Bartlett Landing, which is on
the northeast shore of Clear Lake, there is a small carbonated spring
that, though known locally, has not been often visited and is of little
importance. It lies in an area of altered sediments, mainly shales,
that make up the mountains on the northeast side of the lake and
are considered to belong to the Knoxville formation of Lower Cre-
taceous age.1
CARBONATED SPRINGS ON CHALK MOUNTAIN (LAKE 25).
Chalk Mountain lies about 11 miles in a direct line east of north
from the town of Lower Lake, and in the bend of Cache Creek, where
it swings from a westerly to a southerly course. The mountain is
more properly the end of a ridge and received its name because
altered lava, which partly composes it, forms white slopes that make
it a prominent landmark from the north. The lava appears to have
been altered by solf ataric action similar to that which has taken place
at Sulphur Bank (Lake 38). (See p. 98.) On the northwestern side
of Chalk Mountain a spring deposit of lime carbonate extends for
i See Becker, G. F., Geology of the quicksilver deposits of the Pacific slope: U. S. Geol. Survey Mon.
13, Sheet III of Atlas, 1888.