Las Guijas Mine group (Immense Lode; Grand Lode; General Electric Mine; General Electric group of claims; Obregon claims; Black Gold group), Las Guijas Mountains, Arivaca Mining District (Las Guijas Mining District), Las Guijas & San Luis Mountains, Pima County, Arizona, USAi

Regional Level Types
Las Guijas Mine group (Immense Lode; Grand Lode; General Electric Mine; General Electric group of claims; Obregon claims; Black Gold group)	- not defined -
Las Guijas Mountains	Mountain Range
Arivaca Mining District (Las Guijas Mining District)	Mining District
Las Guijas & San Luis Mountains	Mountain Range
Pima County	County
Arizona	State
USA	Country

‡Ref.: Dale, V.B., Stewart, L.A., and McKinney, W.A. (1960), Tungsten deposits of Cochise, Pima, and Santa Cruz Counties., Arizona, U.S. Bureau of Mines Report of Investigation 5650: 102-104.

Wilson, E.D. (1941), Tungsten Deposits of Arizona, Geological Series No. 14, Arizona Bureau of Mines Bull. 148: 37-39.

Sheikh, A.M. (1966) Geology and ore deposits of Las Guijas tungsten district, Pima County, Arizona: Tucson, University of Arizona, M.S. thesis, 44 p.

Sheikh, A.M. (1970) Geology and ore deposits of Las Guijas tungsten district, Pima County, Arizona: Economic Geology: 65(7): 875-882.

Keith, Stanton B. (1974), Arizona Bureau of Geology & Mineral Technology, Geological Survey Branch Bull. 189, Index of Mining Properties in Pima County, Arizona: 105 (Table 4).

Phillips, K.A. (1987), Arizona Industrial Minerals, 2nd. Edition, Arizona Department of Mines & Minerals Mineral Report 4, 185 pp.

Arizona Bureau of Mines file data.

MRDS database Dep. ID file #10039533, MRDS ID #M050230; and, Dep. ID file #10101381, MRDS ID #D000809; and, Dep. ID #10109603, MRDS ID #M050262; and, Dep. ID #10162307, MAS ID #0040190279.

A former small underground W-Au-Ag-Cu-Pb-Zn-Mn-Fluorspar mine group located on 38 patented claims in the western ½ sec. 25 & the eastern ½ sec. 26, T.20S., R.9E., between the General Electric and Soto groups & adjacent to the General Electric group on the West, on private land. Discovered 1900. First produced 1914. Owned at times, or in part, by Whitcomb & Associates; Tungsten Alloys Corp.; Ore Metal & Engineering Corp.; Southwestern Ore Corp.; the General Electric Co.; Tungsten Mining Corp.; Mr. Manuel L. Obregon; and, the Fernstrom Mining Co. Operated by F.H. Parker (1954).

Mineralization is irregular, lensing quartz-fissure veins of Laramide age, containing tungsten ores and base and precious metal mineralization, with fluoruite and manganese, minor sulfides plus magnetite and their oxidation products, hosted in granite. Veins consist of coarsely-crystalline, grayish-white quartz with ore minerals. There is enrichment of gold in the weathered surface area. Psilomelane and fluorite are also present. Veins occur in sericitized and fractured Laramide granitic intrusive at the contact with Cretaceous volcanic breccia. The fault zone strikes N65W. A lamprophyre dike parallels the vein. Sometimes associated with basic dikes. Ore concentration is epigenetic, epithermal veins. Alteration is oxidation which extends to the 10 to 20 foot level. The vein terminates at an intrusive contact on the NW and a NE-SW fault on the SW. The ore is 243.84 meters long, strikes N65-80W and dips 78N with a plunge of 45-85NE.

Local structures include block faulting.

Workings include shallow shafts, tunnel, pit and open cut operations with a 1,500 foot long adit, a 1,000 foot long adit, and some shorter adits. There are 3 levels of workings. Originally worked prior to 1900 for gold and silver, and intermittently since WWI for tungsten. About 2,000 tons of Au-Ag-Cu ore, and over 155,000 pounds of WO3 concentrates are estimated to have been produced.

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Link to USGS MRDS:	10039533

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