The Holcomb district is 20 to 25 miles northeast of San Bernardino, in Tps. 2 and 3 N., Rs. 1, 2, and 3 E.
Activity in this district began in the 1850's, when the Ozier mine was the major producer of gold ore (Wright and others, 1953, p. 77). In the late 1860's, when the gravels of Holcomb Valley were found to be auriferous, prospectors flocked into the area and in a few years took out about $7 million (about 340,000 ounces) in gold (Vaughn, 1922, p. 409). The large placer production seems somewhat questionable, because nowhere else in the literature is any mention made of the Holcomb Valley placers. The lode mines flourished until the early 1900's but have been virtually idle since then. Only 3 ounces of gold was reported from the district during 1950-59. Data are incomplete for the early years, although Wright, Stewart, Gay, and Hazenbush (1953, p. 70-86) estimated the output of a few of the lode mines. Total gold production, including Vaughan's estimate of the early placer output, was about 400,000 ounces, of which about 54,500 ounces was from the lode mines.
The geology of the area has been described by Vaughan (1922, p. 344-411). In the vicinity of the mines the country rock, which is primarily a sequence of Paleozoic sedimentary formations, is complexly folded, faulted, and intruded by the Cactus Granite of Jurassic age. The sedimentary rocks are the Arrastre Quartzite of Early Cambrian age, the Furnace Limestone of Late Cambrian and Ordovician age, and the Saragossa Quartzite of Silurian or Devonian age. Most of the deposits are in quartz veins along limestone-granite contacts or are associated with limestone beds transected by granitic dikes. A few deposits are in thick quartz veins in quartzite. The ore minerals are pyrite, galena, sphalerite, chalcopyrite, pyrrhotite, and free gold. Azurite and malachite are found in the oxidized zones. Considerable amounts of contact metamorphic minerals such as garnet, epidote, wollastonite, and tremolite are found locally with the ore deposits.
The Stedman district is about 7 miles south of Ludlow, in Tps. 6 and 7 N., R. 8 E.
Total gold production, entirely from lode mines, has been in excess of $6 million (291,000 ounces), more than half the total recorded gold production of San Bernardino County (Wright and others, 1953, p. 71). The Bagdad-Chase mine, which is the principal mine, was discovered in 1903, and during 1904-10 it produced $4 1/2 million in gold. Large quantities of copper and silver were also produced from this mine. After 1940 the mine was operated by lessees; however, no production was reported during 1950-59.
The geology of the Bagdad-Chase mine was described briefly by Wright, Stewart, Gay, and Hazenbush (1953, p. 71, 82). The ore is in a mineralized breccia zone between a body of quartz monzonite and rhyolite. The breccia is composed of fragments of both rock types cemented by silica, which carries gold and oxidized copper minerals.
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