Montana Mine group, Ruby, Oro Blanco Mining District (Ruby Mining District), Oro Blanco Mountains, Santa Cruz County, Arizona, USAi

Regional Level Types
Montana Mine group	- not defined -
Ruby	- not defined -
Oro Blanco Mining District (Ruby Mining District)	Mining District
Oro Blanco Mountains	Mountain Range
Santa Cruz County	County
Arizona	State
USA	Country

Ref.: The Resources of Arizona - A Manual of Reliable Information Concerning the Territory, compiled by Patrick Hamilton (1881), Scottsdale, AZ: 45.

Guild, F.N. (1910), The Mineralogy of Arizona, The Chemical Publishing Co., Easton, PA.

Schrader, F.C. (1917), The geologic distribution and genesis of the metals in the Santa Rita-Patagonia Mountains, Arizona, Economic Geology: 12: 237-269.

Tenney, J.B. (1928), The mineral industries of Arizona, Arizona Bureau of Mines Bull. 125: 88.

Andrus, D.E. (1931) Milling methods and costs at the Montana mine concentrator of the Eagle-Picher Lead Co., Ruby, Arizona: U.S. Bureau of Mines Information Circular IC 6497, 15 p.

Head (1931).

Warren, H.V. & R.W. Loofburrow (1932), The occurrence and distribution of the precious metals in the Montana and Idaho mines, Ruby, Arizona. Economic Geology: 27: 578-585.

Wilson, E.D., Cunningham, J.B., and Butler, G.M. (1934), Arizona Lode Gold Mines and Gold Mining (revised 1967), Arizona Bureau of Mines Bull. 137: 188.

Fowler, G.M. (1938) Montana mine, Ruby, in Some Arizona ore deposits: Arizona Bureau of Mines Bulletin 145: 119-124.

Galbraith, F.W. (1947), Minerals of Arizona, Arizona Bureau of Mines Bull. 153: 18, 19, 30.

Fowler, G.M. (1951) Oro Blanco or Ruby district, Chapter V, in Arizona zinc and lead deposits, Part II: Arizona Bureau of Mines Bulletin no. 158, p. 41-49.

Wilson, E.D., et al (1951), Arizona zinc and lead deposits, part II, Arizona Bureau of Mines Bull. 158.

Anderson, R.Y. & E.B. Kurtz, Jr. (1955), Biochemical reconnaissance of the Annie Laurie uranium prospect, Santa Cruz County, Arizona, Economic Geology: 50: 227-232.

Knight, L.H., Jr. (1970) Structure and mineralization of the Oro Blanco mining district, Santa Cruz County, Arizona: Tucson, University of Arizona, Ph.D. dissertation, 172 p., 7 sheets, scales 1:1,200, 1:6,000, 1:16,000, 1:24,000, 1:60,000, 1:62,500, and 1:358,000.

Keith, Stanton B. (1975), Arizona Bureau of Mines Bull. 191, Index of Mining Properties in Santa Cruz County Arizona: 65 (Table 4).

Niemuth, N.J. (1987), Arizona Mineral Development 1984-1986, Arizona Department of Mines & Mineral Resources Directory 29, 46 pp.

Sawyer, M.B., Gurmendi, A.C., Daley, M.R., and Howell, S.B. (1992) Principal Deposits of Strategic and Critical Minerals in Arizona, U.S. Bureau of Mines Special Publication, 334 pp.

Arizona Bureau of Mines file data.

MRDS database Dep. ID file #10039546, MRDS ID #M050255.

A former small underground Pb-Zn-Ag-Cu-Au-(Cd-Sb-As) mine group located in the north (center NE¼) of sec. 5, T.23S., R.11E, on the SE edge of the town of Ruby, on private land. Discovered 1872. Produced 1875- ?, 1928-1940, and closed 1958. Owned at times, or in part, by the Orion Co.; Montana Co.; Zeckendorf; Goldfield Consolidated Mines Exploration Co.; Montana Mines Operations; Miller; and the Maravilla Mineros Corp. Owned by the Eagle-Picher Mining & Smelting Co. (1940). Operated by Mr. Hugo Miller (1940's-1950's); and, the K And K Co. (1986).

Mineralization is lensing, vuggy quartz veins containing sulfides and sulfosalts as fracture fillings, in vugs, and as replacements of quartz and sheared and brecciated wall rock. The "vein" is a replacement by quartz and sulfides of numerous shears arranged en echelon. The en echalon veins are along a fault zone cutting blocks of Cretaceous conglomerate and Laramide diorite that are intruded and offset by later diorite porphyry dikes. The ore zone is 304.8 meters long, 15.24 meters wide, with a depth to top of 7.62 meters, depth to bottom of 228.6 meters, at 220.98 meters thick, striking E-W, dipping 40-90W, and plunging 45W. Host rock units are the Oro Blanco Formation and the Ruby Diorite. Fractures seem to be abundant and well mineralized only in the conglomerate. An associated rock unit is the Sidewinder Quartz Monzonite. Sulfides are oxidized near the surface with enrichment of silver and gold.

Workings include extensive operations from shafts. Workings have a total length of 3,048 meters and a depth of 228.6 meters. There is a vertical shaft & nine levels - stoped from tunnel level to 660 level on the Montana Vein & 300 to 400 (OR 600) - level on the Rough and Ready Vein. This deposit was located in the early 1870's and was worked intermittently on a small scale until 1928 through 1940. Some sporadic work up to 1958. Total production for the group/complex would be some 870,000 tons of ore averaging about 3.5% Pb, 3.5% Zn, 5 oz. Ag/T, 0.5 oz. Au/T and 0.3% Cu. This mine was the largest Pb-Zn producer in the state (1935-1939). It was also the third largest in silver production in 1938. This deposit is believed to be mined out, although the tailings pond represents a possible resource for gold and silver leaching. Early production was largely Au and Ag from the top of the deposit.

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Link to USGS MRDS:	10039546

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