Located near the center of the Cerbat Mountains, which extend north-northwestward from Kingman for about 30 miles, the Wallapai district includes the mining camps of Chloride, Mineral Park, Cerbat, and Stockton.
Unlike the San Francisco district immediately to the southwest in the Black Mountains, where gold is the principal metal, in the Wallapai district lead-zinc ores are prevalent and silver and gold are chiefly byproducts. Many of the veins in the Cerbat Mountains were discovered in the early 1860's by prospectors in search of precious metals (Schrader, 1909, p. 51, 80, 91, 107). Chloride, founded in the early 1870's and named from the character of its rich silver ore, was the first settlement in this area. Ores rich in gold and silver yielded a large production in the 1870's, but activity waned when the price of silver began to decline in 1882. Base-metal ores below the oxidized zone apparently were not mined extensively until the completion of the branch railroad from Kingman to Chloride in 1899 (Nolan, in Hewett and others, 1936, p. 19). Thereafter leadsilver ores were mined, and subsequent improvement in milling methods led to exploitation of complex lead-zinc ores (R. M. Hernon, in Arizona Bur. Mines, 1938, p. 111). Zinc-lead mining reached its peak from 1915 through 1917 owing to high metal prices during World War I, declined abruptly after 1917, and thereafter exploitation was confined to veins with a relatively high gold content. Gold production began to increase in 1935 and reached its peak in 1937-38 (Dings, 1951, p. 126). After 1942, activity declined sharply, and from 1950 through 1956 gold production was less than 100 ounces annually. None was recorded for 1957-59. From 1904 through 1956 the mines of the district produced 125,063 ounces of gold. Dings (1951, p. 125) estimated the value of combined metals produced before 1904 at $5 million, but the amount of gold represented in this total is unknown.
The rocks of the district consist of granite, gneiss, and schist of Precambrian age, stocks and irregular bodies of granite and gabbro probably Mesozoic in age, and still younger dikes of lamprophyre, rhyolite, granite pegmatites, and porphyritic granite. The veins, which occur in all rock types, occupy fault fissures; a few follow dikes (Dings, 1951, p. 127-139).
The veins that yield most of the gold consist mainly of fine-grained quartz with pyrite, sphalerite, galena, and chalcopyrite. The veins locally include arsenopyrite, proustite, molybdenite, and argentite and rarely include tennantite, pearceite, and polybasite. Other gangue minerals are calcite, manganiferous siderite, and rarely rhodochrosite. Gold and silver are in the galena and sphalerite. The sulfides have been moderately oxidized to depths of about 75 to 200 feet, and partly oxidized ore has been found down to 600 feet. The principal ore minerals in the oxidized zone are cerargyrite, native silver, cerussite, and native gold, and the most common gangue minerals are limonite and limonitic quartz (Dings, 1951, p. 141-142).
The Weaver district is in the northern Black Mountains, 10 to 25 miles west and northwest of Chloride. The Mockingbird, Pyramid, and Pilgrim camps are on the eastern slope; the Virginia camp is on the western slope.
Gold was discovered in 1904 in the Pilgrim camp; however, miners had found gold as early as 1892 in the Gold Bug camp, several miles north of the Weaver district (Schrader, 1909, p. 214, 217). Incomplete production records credit the district with about 1,900 ounces of gold before 1932 (Nolan, in Hewett and others, 1936, p. 17, 19). The period of greatest activity was 1932-42, after which the district declined to the extent that only 138 ounces of gold was reported for 1943-59. Total gold production of the district through 1959 was about 63,200 ounces.
The oldest rocks of the district are Precambrian granite, gneiss, and schist, which are exposed mainly along the eastern slope of the Black Mountains and are overlain on the west slope by Tertiary volcanic rocks intruded by porphyry dikes (Wilson and others, 1934, p. 78-79). The ore, which yields native gold and small amounts of silver, is in veins chiefly in the volcanic rocks. The gangue is quartz, adularia, calcite, and local hematite.
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