Page 333 - 1915, Springs of CA.

ARTESIAN SPRINGS. 313
yards in diameter. Its immediate yield is perhaps 15 gallons a
minute, but this is increased by other seepages, so that the combined
flow of the two springs and the seepages forms a stream of perhaps
30 gallons a minute. Much soft brown deposit along the course of
the overflow and in the marshy land possibly consists to large extent
of Crenothrix, a vegetable organism that secretes iron.
IRON SPRINGS NEAR LAKE TAHOE (PLACER 12).
A mile northwest of McKinney, on the western side of Lake Tahoe,
two small iron springs rise in the woods on a gentle slope about 350
yards above the main wagon road and form pools about a foot in
diameter and a foot in depth, 4 yards apart, which are used for
drinking. The water tastes distinctly ferruginous and has deeply
iron stained the soil for about 75 yards below the springs. The
staining is probably caused by the fact that the water contains a
small amount of carbon dioxide, which holds the iron in solution until
this gas has escaped, when the iron is precipitated and deposited
along the overflow course.
The springs issue from lake deposits of sand and gravel near the
base of steep slopes of andesitic lava.
IRON SPRING NEAR CISCO (PLACER 1).
A cold iron spring that yields perhaps 8 gallons a minute is situated
in a small depression in a patch of alders on a gentle slope on the
southern side of the canyon of South Fork of Yuba River, half a mile
north of Cisco railroad station and 100 yards south of the wagon
road. The soil is deeply iron stained for a number of yards along
the overflow channel. The spring is well known locally, as it fur-
nishes excellent cold drinking water. The surrounding rocks are
the slates and schists derived from them that have been mentioned
in speaking of the sulphur springs near South Fork of Yuba River
(Placer 2, p. 284), a mile or two upstream from the iron spring.
ARTESIAN SPRINGS.

SPRINGS PREVIOUSLY DESCRIBED.
Many of the springs that rise in the alluvial valleys of the State
yield considerable good water that is noticeably above a normal tem-
perature and that is apparently forced to the surface through the
deep alluvial deposits by artesian pressure. Several springs in
Sonoma County, notably those on McEwan ranch (Sonoma 14, p.
114), Los Guilicos Warm Springs (Sonoma 15, p. 114), and the Warm
Springs of the State Home at Eldridge (Sonoma 16, p. 114), which
have been described among thermal springs, may also be mentioned
in connection with artesian springs, as they rise in tuffaceous lava,