Yavapai County Arizona Gold Production
The Lynx Creek-Walker district is about 7 miles southeast of Prescott. Lynx Creek is one of the most productive placer streams in the State; moreover, lode mines in the Walker camp have yielded considerable gold, silver, copper, and lead.
The placers were discovered by a party of California miners in 1863, and as they worked upstream they found the gold-bearing veins of the Walker camp (Lindgren, 1926, p. 108-109). The richest placers were depleted in the early days, but small and intermittent placer operations continued for many years. From 1927 through 1941 large-scale dredging operations were successful, but from 1942 through 1959 the placer mining was desultory and was carried out on a small scale. In the Walker camp only oxidized ore was mined in the early years and was worked in arrastres. Deep mining into the sulfide zone presumably was begun some time before 1910. Lode production probably was never very large, and it fluctuated considerably but was almost continuous from 1905 through 1952.
According to Lindgren (1926, p. 109) the placer output through 1924 was about $1 million, most of which was extracted in the early years. Wilson (1952, p. 39, 42) reported that production before 1881 was estimated at $1 million (48,379 ounces), and from 1900 to 1949 it was about $1 million, mostly during 1933-42. Total gold output of the district through 1959 was about 140,000 ounces: 97,000 ounces from placers and 43,000 ounces from lodes.
Underlying the district are schists of the Yavapai Series and the Bradshaw Granite intruded first by a granodiorite stock and later by a number of rhyolite porphyry dikes. The ore deposits are in sulfide-bearing quartz veins that transect the granodiorite. Ore minerals are pyrite, sphalerite, chalcopyrite, galena, and tetahedrite. Gold is contained in chalcopyrite, and gold and silver seem to be associated with galena and tetrahedrite. The ores were mined mainly for gold (Lindgren, 1926, p. 111).
MARTINEZ DISTRICT
The Martinez district is in southwestern Yavapai County in the southeastern Date Creek Mountains a few miles northwest of Congress.
Gold was produced almost entirely from quartz veins and mostly from the Congress mine. The first discoveries were made in 1870, but the ore was not free milling and thus progress was impeded until a cyanide plant was built in 1895. High production was maintained until 1910 (Wilson and others, 1934, p. 69-71). Except for a span of intensive operation by lessees during 1938-42, the mine was virtually idle from 1910 through 1959. The total minimum gold production of the Congress mine from 1887 through 1959 was about 396,300 ounces.
The eastern Date Creek Mountains consist of coarse-grained granite, intruded by pegmatites, aplites, and basic dikes. The gold deposits are along low-dipping faults in veins that consist of coarse-textured quartz with pyrite and some galena (Wilson and others, 1934, p. 69). At the Congress mine the most productive veins are within the basic dikes, mostly near their footwalls. Veins in the granite are of lower grade; they carry small amounts of galena and larger amounts of silver (Staunton, 1926, p. 769). Ore has been mined to a depth of 4,000 feet.