La Paz District (Weaver District), Dome Rock Mts, La Paz Co., Arizona, USA

‡Ref.: Bancroft, H. (1911), Reconnaissance of the ore deposits in northern Yuma County, Arizona, USGS Bull. 451: 78-86.

Jones, E.L., Jr. (1916b) Gold deposits near Quartzsite, Arizona, in Contributions to economic geology, 1915, Part I: Metals and nonmetals except fuels: U.S. Geological Survey Bulletin 620: 45-57.

Wilson, E.D., et al (1934)(revised 1967), Arizona Bureau of Mines Bull. 137: 135-136.

Wilson, E.D. (1961) Gold Placers and Placering in Arizona. Arizona Bureau of Mines Bull. 168 (revised 1978): 25-29.

Johnson, M.G. (1972), Placer gold deposits of Arizona, USGS Bull. 1355, 103p.: 76-78.

Keith, Stanton B. (1978) State of Arizona Bureau of Geology and Mineral Technology, Geological Survey Branch Bull. 192, Index of Mining Properties in Yuma County, Arizona: 158 (Table 4).

Arizona Bureau of Mines file data.

A Au-Ag-W-Mn-Cu-Pb-kyanite-Th-REE mining area located in T.2-6N., R.20 & 21 W., on the West side and northern portion of the Dome Rock Mountains. Started in the 1860's.

The area is made up of sedimentary and igneous schists, locally intruded by granite. Larger and more persistent veins generally occur parallel to the schistosity and small gash veins cut across the scistosity.

Mineralization is varied: (1): Gold placer deposits, in gravels of numerous gulches and in terrace gravels bordering the washes, derived from small, lensing, gold-bearing quartz veins and veinlets in Mesozoic and early Tertiary metamorphic and granitic rocks; (2) Spotty gold and silver mineralization with some base metals in quartz fissure veins in Mesozoic metamorphic rock, intruded by Mesozoic or early Tertiary granitic rock; (3) Sporadic tungsten mineralization in contact metamorphic deposits along faults or intrusive contacts and associated with marble beds in Mesozoic metamorphic beds; and, (4) Manganese oxides in iregular bodies along bedding plane fractures in Mesozoic metamorphic rocks.

This district features extensive placer operations in gulches and on terraces from the 1860's, mainly prior to 1900. Several relatively small scattered mining operations for precious and base metals from the late 1800's to about 1960. Tungsten and manganese prospecting and mining were carried on during periods of premium prices. Total estimated placer production would be around 100,000 oz. gold with about 25,000 oz. silver. Mine production of precious and base metals would amount to some 11,200 tons of ore containing about 2,400 oz. gold, 1,000 oz. silver, 8 tons of copper, and 2 tons of lead. Some 5,000 tons of tungsten ore containing about 0.4% WO3 and some 400 long tons of 41-51% Mn ore were also produced.