Aztec Mine (Aztec group of claims; Aztec Mine group; Andes group), Aztec Gulch, Alum Gulch, Harshaw Mining District, Patagonia Mountains, Santa Cruz County, Arizona, USAi

Regional Level Types
Aztec Mine (Aztec group of claims; Aztec Mine group; Andes group)	Mine
Aztec Gulch	Gulch
Alum Gulch	Gulch
Harshaw Mining District	Mining District
Patagonia Mountains	Mountain Range
Santa Cruz County	County
Arizona	State
USA	Country

‡Ref.: Schrader, F.C. & J.M. Hill (1915), Mineral deposits of the Santa Rita and Patagonia Mountains, Arizona, USGS Bull. 582: 263-264.

Tenney, J.B. (1927-1929) History of Mining in Arizona, Special Collection, University of Arizona Library & Arizona Bureau of Mines Library: 313.

Moores, R.C., III (1972) The geology and ore deposits of a portion of the Harshaw district, Santa Cruz County, Arizona: Tucson, University of Arizona, M.S. thesis, 98 p.

Simons, F.S. (1972) Mesozoic stratigraphy of the Patagonia Mountains and adjoining areas, Santa Cruz County, Arizona, in Mesozoic stratigraphy in southeastern Arizona: U.S. Geological Survey Professional Paper 658-E: E22.

Keith, Stanton B. (1975), Arizona Bureau of Mines Bull. 191, Index of Mining Properties in Santa Cruz County Arizona: 56 (Table 4).

Niemuth, N.J. & K.A. Phillips (1992), Copper Oxide Resources, Arizona Department of Mines & Mineral Resources Open File Report 92-10: 16 (Table 1).

U.S. Bureau of Mines files, Aztec Mine group.

Arizona Bureau of Mines file data.

MRDS database Dep. ID file #10048354, MRDS ID #M899945; and, Dep. ID #10161874, MAS ID #0040230033.

A former small surface and underground Cu-Ag-Pb-Au-Zn mine located on 24 claims in North-central sec. 19, T.22S., R.16E. (Elgin 15 minute topo map), 2 miles south of Patagonia, in the NW slope of Red Mountain, in the upper part of Aztec Gulch, a NE tributary of Alum Gulch, at an elevation of about 4,850 feet, on National Forest land. Discovered in 1925 by R.R. Richardson and Associates. First produced in 1916. Owned by R.R. Richardson (early 1900's), of Patagonia. Other operators/owners included Sanders and Harrison; and, Mr. Ed Bollinger. The Andes Mine of the Aztec Mine group is located on the Andes vein.

Mineralization is disseminated and small banded lenses of copper carbonates and sulfides in a strongly sericitized fracture zone in Cretaceous-Tertiary Laramide rhyolite, enriched in places by a system of cross fractures. Ore concentration included the secondary replacement of rhyolite by small, irregular deposits of ore. Surface oxidation exists to unknown depths. The ore zone is 609.6 meters long, 15.24 meters wide, strikes N-S and dips 75SE.

Local rock is a large area of mineralized or partly mineralized rhyolite which is medium- to coarse-grained, partly porphyritic, and in places crudely and dimly banded and bedded.

The principal exposures are in the southern part of the group on claims Nos. 8 & 11. Here the rhyolite is more or less heavily impregnated with pyrite and chalcopyrite and is coated with chalcocite, bornite and malachite. The latter minerals are particularly concentrated as secondary replacement deposits in a 12 foot lode or ore bed which dips 75ºSE, and is reported to have an extent of 2,000 feet, mostly to the northeast of the main opening.

In places the openings reveal the deposit to be at least 50 feet in width and to have a horizontal extent of more than 100 feet. Some of the ore is banded or consists of shoots of relatively pure secondary chalcocite and chalcopyrite 1 inch (2.5 cm) in maximum width and containing inclusions of orthoclase and quartz of the replaced rhyolite. Nearly everywhere the ore minerals are surrounded by a fringe (rim) of muscovite, or are embedded in a mass of it, and the feldspar and quartz show a tendency to a radial arrangement around the ore.

Local structures include E-W and N-S-trending faults. Thick-bedded, very fine-grained volcanics are associated with Red Mountain.

Tectonic elements include the Red Mountain Fault Block with downthrow to the north.

Workings include a 1,500 foot tunnel, a 90 foot inclined shaft and a 30 foot open cut plus 600 feet of drifts, crosscuts and raises. Workings total 676.66 meters in length and 182.88 meters in depth. A few tens of tons of 7% Cu (+ 5 oz/ton Ag) ore were produced in the early 1900's.

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Link to USGS MRDS:	10048354

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