Location and History
This district is in southwestern San Bernardino County about 30 miles northeast of San Bernardino on the north side of the San Bernardino Mountains. It also has been known as the Silver Reef district. The district was organized in 1870. An English concern organized the Santa Fe group in 1890 to work the area on a large scale, but work stopped soon afterward and prospecting was minor during the early 1900s. The Santa Fe group was re-opened in 1921 and operated continuously until 1940. In this last operation, the production amounted to $300,000.
Geology and Ore Deposits
The area is underlain by granitic rocks, mica schist, gneiss, and a limestone belt. A mineralized zone known as the ArlingtonSanta Fe lode occurs in a thrust fault that strikes west and dips north. The ore consists of hematite-bearing gouge and a limestone breccia. Several ore bodies yielded up to one ounce of gold per ton. The ore zones are up to 75 feet thick and 1000 feet long. Much of the output in the district has come from the Santa Fe groups.
Bibliography
Cloudman, H. C., et al., 1919, San Bernardino County, the Black Hawk district: California Mining Bureau Rept. 15, pp. 797-798.
DeGroot, Henry, 1890, The Black Hawk district: California Mining Bureau Rept. 10, pp. 523-525.
Storms, W. H., 1893, Black Hawk district: California Mining Bureau Rept. 11, pp. 364-365.
Woodford, A. D., and Harris, T. F., 1928, Geology of Black Hawk Canyon: California Dept. Geol. Sci., Bul., vol. 17, pp. 265-304.
Wright, L.A., et al., 1953, San Bernardino County, Santa Fe mines: California Jour. Mines and Geol., vol. 49, p. 80.
