Page 105 - 1915, Springs of CA.

HOT SPRINGS. 99

The analyses indicate that the waters are strongly primary alkaline
in character. They differ chiefly in tertiary alkalinity and the relative
prominence of salinity and alkalinity. The difference would be
practically eliminated if sulphuric acid or sulphate of iron or other
heavy metals were added to the water of the Hermann shaft.
The slopes near the Sulphur Bank mines are composed mainly of
sediments that have been considered Lower Cretaceous in age, but
where the waters rise the rock is basalt that has been extensively
altered by solf ataric action.
In his description of the quicksilver deposits atthisplaceBecker * has
remarked on the apparent absence of any quicksilver minerals in
solution and has spoken of the presence of boron in the water. The
boron and the thermal character of the water are especially note-
worthy in connection with the presence of the lava at this locality.
A small cold carbonated spring that issues from the gravel near the
lake edge, one-fourth mile west of the Hermann shaft, may also be
mentioned in connection with the lava at Sulphur Bank.
Warm carbonated waters emerge at a number of places along the
western border of Clear Lake, notably at Soda Bay and at John
Behr's ranch, and are described with the carbonated springs (pp. 191-
193), but are here mentioned as they are also thermal and rise from
volcanic rocks.
WILBTJR HOT SPRINGS (COLTJSA 9).
In the valley of Sulphur Creek, in southwestern Colusa County
a region where considerable mining for quicksilver has been carried
on are several groups of springs that yield hot sulphureted water.
The lowest, easternmost group is at Wilbur Hot Springs, whicn has
been a resort for more than 40 years. It was originally known as
Simmons Hot Springs, and the resort to which the name Wilbur Hot
Springs was applied was 4 miles to the northwest, near the Elgin
quicksilver mine; a number of years ago, however, after the hotel at
the latter place burned, the Simmons property was purchased by the
owners of Wilbur Hot Springs and the upper place was abandoned.
In 1908 the present Wilbur Hot Springs (PL IV, D, p. 32) again changed
ownership, and most of the buildings, which were in poor condition,
were removed and new cottages built.
The hot springs issue along the borders of Sulphur Creek, for a
distance of about one-half mile on the Wilbur property, but are
mainly in a barren, saline area that borders the west side of the creek
from 75 to 200 yards west of the hotel. The position and approxi-
mate extent of this area are shown at the left in Plate IV, D. The
principal springs have been numbered by the owners, beginning at
the western border of the property, on the assumption that eventually

1 Op. cit., pp. 259, 260. A detailed description of the geology at Sulphur Bank is given on pp. 251-257.