Yavapai County Arizona Gold Production
The Tiptop district is in the southern foothills of the Bradshaw Mountains in southeastern Yavapai County, about 45 miles north-northwest of Phoenix.
The history and production of the district is mainly that of the Tiptop mine (Lindgren, 1926, p. 180). This mine, located in 1875, yielded about $2 million probably all in silver and gold, before 1883, when it was closed. The mine was reopened from 1886 to 1888, but apparently it has been closed since that time. A small amount of tungsten ore was mined, probably during World War I. Since then the district has been dormant, except for minor activity during the 1930's and early 1950's. Lindgren (1926, p. 180) considered the estimated total production of $4 million somewhat high. Total gold production through 1959 was about 10,000 ounces.
The host rock is the Bradshaw Granite which intruded a north-trending belt of Yavapai Series, exposed just east of the district. The granite is cut by dikes of rhyolite porphyry and is overlain by a remnant of Tertiary lava flows at the south end of the district (Lindgren, 1926, p. 179-180).
The ore deposits are fissure veins in the granite. The principal gangue mineral is fine to coarse quartz, and some druses are coated with chalcedony. The ore minerals, in paragenetic order, are wolframite, arsenopyrite, pyrite, sphalerite, bornite, and galena. Cerargyrite and ruby silver were common in the oxidized ore; antimonial silver minerals and native silver were probably also present. Some veins rich in galena contained gold and some silver (Lindgren, 1926, p.181-182).
WEAVER-RICH HILL DISTRICT
The Weaver-Rich Hill district is in southwestern Yavapai County along the southwestern front of the Weaver Mountains, 5 to 8 miles east of Congress. Both lodes and placers have been important sources of gold in this district.
An accidental discovery of gold nuggets on top of Rich Hill in the early 1860's kindled interest in the area and before long gold placers along Weaver and Antelope Creeks and the lode deposit at the Octave mine were found (Wilson, 1952, p. 43). By 1883 the placers had yielded $1 million in gold, but thereafter the deposits were worked sporadically and were idle from 1952 through 1959.
Little development of the Octave mine was attempted until the perfection of the cyanide process in the 1890's. Between 1900 and 1905 gold and silver ore worth $1,900,000 was mined. Activity declined after 1905, and the mine was closed in 1930. Under new ownership of the American Smelting and Refining Co., the mine was reopened in 1934 (E. D. Wilson, in Arizona Bureau of Mines, 1938, p. 131) and was worked until December 1942 (Woodward and Luff, 1943, p. 258). Lode production of the district declined sharply in 1943 and was negligible through 1959.
Placers in the district are credited through 1959 with about 104,000 ounces of gold and lodes with about 204,000 ounces, a total of 308,000 ounces. All but about 1,500 ounces of the lode gold came from the Octave mine.
The country rock of the district is mainly granite and quartz diorite with lenses and septa of schist. These rocks are cut by dikes of pegmatite, aplite, and diabase (Wilson and others, 1934, p. 66-68). The veins in the district occur along low-angle fault zones that are chiefly in the granite, but some are in the schist. The main Octave vein, which is in granitic rocks (Nevius, 1921, p. 123), consists of coarse white quartz that carries irregular masses, disseminations, and layers of fine-grained pyrite, galena, and sparse sphalerite and chalcopyrite and a little native gold. Most of the gold is contained in the galena (Wilson and others, 1934, p. 67, 68).