Montana Mine (Miller-Hansen group; Eagle Picher Mine), Montana Mine group, Ruby, Oro Blanco Mining District (Ruby Mining District), Oro Blanco Mountains, Santa Cruz County, Arizona, USAi

Regional Level Types
Montana Mine (Miller-Hansen group; Eagle Picher Mine)	Mine
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

A former surface and underground mine. Initially a Au-Ag mine, subsequently a Pb-Zn-Cu mine located in the SW¼NE¼ sec. 5, T23S, R11E, near Ruby, on National Forest land. Claims patented in 1907 by L. Zeckendorf; subsequently owned/operated by the Goldfield Consolidated Mines Exploration Co. (1916-1918); the Eagle Picher Lead Co. (later the Eagle-Picher Mining and Smelting Co.)(1926-May, 1940); and, Hugo Miller of Nogales (circa 1950).

Mineralization is a large ledge of carbonate ore known as the Montana vein. This vein trends East-West along a shear zone at which conglomerate-Ruby diorite contact at a jagged surface, as numerous projections of the diorite extending a few feet into the conglomerate. The vein ranges in width from mere stringers to more than 40 feet wide. The ore zone is 305 meters long, 15 meters wide, with a depth to top of 7.6 meters, and a thickness of 221 meters. It strikes E-W and dips 40 to 90N. All of the orebodies are in shear zones along this contact or in the conglomerate. Some shear zones branch with barren country rock between branches. Wide orebodies in the conglomerate change to small stringers in the diorite. The shear zones dip from 40º N. to almost vertical. The Montana vein can be traced on the surface for about 3,000 feet, in part as bold outcrops of quartz several hundred feet long and 50 feet wide. The oreshoots pitch about 45º westward. Ore control was the W to NW fault. Ore concentration was hydrothermal enrichment. The Ag mineral present is undetermined.

The rocks in and around the mine consist largely of andesite, quartz monzonite, conglomerate, diorite of various types and several ages, and rhyolite and allied rocks and tuffs (Oro Blanco Formation; Ruby Diorite; Sidewinder Quartz Monzonite). Small patches of shale occur in a few scattered areas.

Workings include a 100 foot tunnel, shaft & drifts (1928). A 10-stamp mill was erected in 1891 and abandoned in 1893. Largest producer of Pb & Zn in Arizona (1935-1939) and third largest producer of silver for 1938. A total of some 773, 197 tons of ore was milled during 1928-1940. Grades for record: 3.5% Pb, 3.5% Zn, 5 Troy ounces/short ton Ag, 0.5 Troy ounce/short ton Au, 0.3% Cu.

Other Databases

Link to USGS MRDS:	10207565

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References