Florida Mine, Robinson property (Robinson group), Stone Cabin Canyon, Old Baldy Mining District, Pima County, Arizona, USAi

Regional Level Types
Florida Mine	Mine
Robinson property (Robinson group)	Property
Stone Cabin Canyon	Canyon
Old Baldy Mining District	Mining District
Pima 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: 168-169.

Full, Roy P. (1970) Indian Claims Commission docket 345, VIP 298-301.

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

Arizona Bureau of Mines file data.

MRDS database Dep. ID file #10065179, MRDS ID #TC40224; and, Dep. ID #10234374, MAS ID #0040190487.

A former small underground Ag-Cu-Pb mine located in sec. 32, T19S, R15E, on the Robinson property. Operated by Jim Olmstead, Double Tough Mines (1986). NOTE: Alternate coordinates provided 31.75167N, 110.83667W.

Mineralization involves a NW-SE fault or shear zone traversing rhyolite, andesite, and diorite (?) porphyry. The zone is reported to be mineralized for a length of about 1,500 feet, the main ledge or vein being in general 15 feet or more in width.

The shear zone is in red altered andesite and dips 80ºSSW. This zone is comprised of a mixture of clay, brecciated rock fragments calcite, limonite, and secondary copper minerals comprising a copper ore reported to contain about 60 oz. Ag/T.

The hanging wall is fine-grained, dark gray diorite porphyry, consisting largely of acidic plagioclase with a considerable propertion of alteration products, chlorite and epidote, and with magnetite, a conspicuous accessory, mostly altered to hematite. Here and there the rock also contains stringers and veinlets of chalcopyrite, which seem to be primary.

The footwall is a much-altered red rock with a microcrystalline groundmass of acisic plagioclase and hematite, and the first 2 to 4 feet of vein or ledge material next to it consists of fragments of rock and gangue-like clay mixed with copper carbonates and limonite, and is reported to avergae 12% Cu and 25 oz. Ag/T. The rest of the ledge, which averages 10 feet in width, is composed of rock similar to that forming the hanging wall but crushed or intensely jointed into cuboidal fragments with faces about ½ to 1 inch square, which are filmed with limonite and copper carbonates. Some pyrite and chalcopyrite are also disseminated in the rock, and the whole 10 feet constitutes ore.

Workings are comprised of several 50 to 100 foot long tunnels and shallow shafts (Florida tunnel and shaft and the Invincible tunnel) aggregating about 500 feet of workings. The Florida shaft is on the fault zone at an elevation of 6,340 feet, near the top of the ridge.

The Invincible tunnel is at an elevation of 6,125 feet and is essentially a 50 foot drift run SSE in the mineralized zone.

Other Databases

Link to USGS MRDS:	10065179

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