Boriana Mines, Boriana Canyon, Boriana District, Hualapai (Hualpai) Mts, Mohave Co., Arizona, USA

Ref.: Wilson, E.D. (1941), Tungsten deposits of Arizona, Arizona Bureau of Mines Bull. 148: 11-14.

Hobbs, W.W. (1944), Tungsten deposits in the Boriana district and the Aquarius Range, Mohave County, Arizona, USGS Bull. 940-I: 247-264.

Palache, Charles, Harry Berman & Clifford Frondel (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition, Volume II: 1070, 1077.

Galbraith, F.W. & Brennan (1959), Minerals of Arizona: 79.

Dale, V.B. (1961), Tungsten deposits of Gila, Yavapai, and Mohave Counties, Arizona, U.S. Bureau of Mines Information Circular 8078: 72-8.

Lemmon, D.M., and Tweto, O.L. (1962) Tungsten in the United States, USGS map, MR-25.

Elevatorski, E.A. (1978), Arizona Industrial Minerals, Arizona Department of Mineral Resources, Minerals Report No. 2.

Lemmon, D.M., unpublished data.

Conway, C.M., et al (1990), USGS Bull. 1737-E: E8-E9.

Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd. ed.: 133, 198, 404, 423.

Arizona State Land Department Mineral map.

USGS Prescott map.

Arizona Department of Mineral Resources (ADMR) files.

Arizona Department of Mineral Resources (ADMR) Mohave Custom Mill proj. card file.

MRDS database Dep. files #10008548, 10234839 & 10234369.

A W-Cu-Ag-Au mine located in secs. 7, 9, 18, T.18N., R.15N., & sec. 12, T.18N., R16W. Comprised of 40 unpatented claims. Located 18 road miles NE of Yucca at about 5,000 feet of altitude. Owned by the Molybdenum Corp. of America (circa 1941).

Mineralization is wolframite-scheelite bearing quartz veins in fine-grained muscovite schist, mainly in 2 composite lodes of quartz veins 90 to 135 feet apart (East lode and West lode). Each vein is comprised of 2 to 10, or even 20, parallel quartz veins and stringers, separated by schist, within widths of a few feet to 20 feet or more. At least 4 of the composite lodes have been encountered within a width of 200 feet. The vein system strikes N.30º to 40ºE., conforming to foliation of the schist, and dips vertically to 75ºSE. Country rock is a belt of schist, locally ¼ to ½ mile wide, that strikes N.30º to 40º E., and dips as the veins, and extends for several miles across the range. In the vicinity of the mine, the schist is a thinly laminated to blocky gray slate with some sandy phases; abundant fine-grained sericite and chlorite mark its parting planes. The schist belt is intruded on both sides by coarse-grained biotite granite which grades into gneiss near its contacts. Dikes of aplite and pegmatite cut both the gneiss and the schist.

Alteration is silicification and sericitization. The ore-bearing veins appear to have originated in the granite intrusive at the north end of the vein zone. The richer veins occur in areas where the phyllite is softer, while the veins are more narrow and lean in areas with hard and blocky phyllite. Ore control is attributed to foliation in the phyllite and certain joint planes in granite; fracturing; and lithology. Minor faulting offsets the veins.

The deposit was known prior to 1908 and produced comparitively little until 1915, thereafter production increased until it was Arizona's leading tungsten producer in 1918 and again, during 1933-1937 it was the leading producer in Arizona and probably the second largest producer in the USA. Also operated 1951-1957 and 1979-1980.

Workings were 1,100 feet deep and included 9 levels plus 3 sub-levels. More than 15,500 feet of drifts. The 5th level was the main haulage adit. The mine produced 98% of 120,413 short ton units of WO3, which equals 2,400,000 pounds of WO3. The principal oreshoot on the West lode had been mined from surface to the 7th. level by June 15, 1941, with a stope length of 8,700 feet; similarly, on the East lode, an ore shoot with a stope length of 1,000 to 1,100 feet had been mined from above the 3rd. level to the 7th. level.