Location and History
The Confidence district is in west-central Tuolumne County between Twain Harte and Long Barn and about 15 miles northeast of Sonora. It is in the Sierra Nevada East Gold Belt and adjoins the Soulsbyville district on the northeast (see fig 24, p. 122). This region was first placer-mined during the gold rush, and lode mining began shortly afterward. The Confidence mine was worked on a large scale until around 1912. Some of the mines were active in the 1930s, and the district was later prospected for tungsten.
Geology
The mines in this district are located chiefly in a southwest-extending arm or "peninsula" of granitic rocks of the main Sierra Nevada batholith (see fig. 24). The principal rock is granodiorite; slate, mica schist, phyllite, and quartzite lie to the sourh. Fine-grained dioritic dikes are present and commonly are associated with the gold-quartz veins. Also present are small bodies of tungsten-bearing tactite, which occur as roof pendants in the granitic rocks.
Ore Deposits
The are bodies occur in north to northwest-striking quartz veins that usually range from one to five feet in thickness. The are contains free gold and often abundant sulfides, especially galena, which often is associated with gold. The Confidence vein was mined to an inclined depth of 1200 feet.
Mines
Casa Madera, Corona, Confidence $4.25 million, Excelsior $420,000, Fair Oaks, Gem, Geraldine, Green $200,000, Humbug, Lucky Strike, Morning Glory, Red Cloud, Ripperton, Ryan, Thunderbolt, Too Far North, Wall Street.
Bibliography
Logan, C. A., 1949, Tuolumne County, Confidence mine: California Jour. Mines and Geology, vol. 45, pp. 61-62.
Preston, E. B., 1893, The Confidence mine: California Min. Bur. Rept. 11, p. 503.
Storms, W. H., 1900, Confidence mine: California Min. Bur. Bull. 18, pp.136-137.
Tucker, W. B., 1916, Tualumne County, Confidence mine: California Min. Bur. Rept. 14, p. 142.
Turner, H. W., and Ransome, F. l., 1898, Big Trees folio: U. S. Geol. Survey Geol. Atlas af the U. S., folio 51, 8 pp.
