Location and History
The Sulphur Creek mercury-gold district is in the southwest corner of Colusa County and in a small adjacent area in Lake County. It is about 20 miles southwest of Williams and just west of Wilbur Springs. Gold was discovered here in 1865, but the chief period of production was from 1880 to 1890, with a minor output since. The total gold output of the district is valued at about $109,000. The principal source of gold has been the Manzanita mine, but some has been recovered from the Cherry Hill and Clyde mines. The Manzanita is one of the few mercury mines that also has been operated as a gold mine.
Geology and Ore Deposits
The deposits consist of narrow seams of siliceous sinter containing incrustations of free gold in the oxidized zone and auriferous pyrite at depth. Usually the gold is associated with fine-grained cinnabar but not always. Some placer gold has also been recovered here. Native sulfur and bituminous matter are present. Country rock is sandstone and shale with several bands of serpentine. Hot spring action apparently has been important in the formation of the mineral deposits in the district; ascending solfatoric waters invaded the sandstone and shale and leached out the more soluble material. Gold, cinnabar, sulfur compounds, and siliceous sinter were then deposited.
Bibliography
Becker, G. F., 1888, Quicksilver deposits of the Pacific slope: U.S. Geol. Survey Mon. 13, pp. 367-368.
Bradley, W.W., 1918, Quicksilver resources of California, Manzanita mine: California Min. Bur. Bull. 7B, pp. 38-39.
Logan, C.A., 1929, Colusa County, Sulphur Creek district: California Div. Mines and Mining Rept. 25, pp. 288-290.
