Gold Districts of California
Bulletin 193 California Division of Mines and Geology 1976
Table of Contents
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Location and History
This district is in the vicinity of the town of Mariposa at the southeast end of the Mother Lode gold belt. The Mariposa mine was reported to have been discovered in 1849 by Kit Carson, and the first stamp mill in California was installed there that same year. Much of this district was part of the Las Mariposas Grant of General John C. Fremont. The old courthouse in Mariposa erected in 1854 is the oldest continuously used courthouse in California. The mines were worked until the early 1900s and again during the 1930s. The Mariposa mine has been prospected in recent years.
Geology and Ore Deposits
The district is underlain by northwest-trending belts of slate of the Mariposa Formation (Upper Jurassic), setpentine, and greenstone. There are several massive quartz veins in slate or greenstone. The ore contains free gold, pyrite, and arsenopyrite, which often is associated with highgrade ore. The Mariposa mine has been developed to an inclined depth of 1500 feet.
Evans II, Kane, Mariposa $2,395,000, Stockton Creek, Stockton Creek Tunnel.
Bowen, O. E., 1957, Mariposa County, Mariposa mine: California Jour. Mines and Geology, vol. 53, pp. 128-130.
Logan, C. A., 1935, Mother Lode gold belt-Mariposa County: California Div. Mines Bull. 108, pp. 180-190.
Ranwme, F. L., 1900, Mother Lode district folio: U.S. Geol. Survey Geol. Atlas of the U.S., folio 63, 11 pp.
Storms, W. H., 1900, The Mariposa mine: California Min. Bur. Bull. 18, pp. 142-143.
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