‡Ref.: Schrader, F.C. & J.M. Hill (1915), Mineral deposits of the Santa Rita and Patagonia Mountains, Arizona, USGS Bull. 582: 220-239.
Rohrbacker, R.T. (1964) Geology of the Temporal Gulch-Mansfield Canyon area, Santa Cruz County, Arizona: Tucson, University of Arizona, M.S. thesis, 81 p.
Drewes, H.D. (1967) A geochemical anomaly of base metals and silver in the southern Santa Rita Mountains, Santa Cruz County, Arizona, in Geological Survey research 1967: U.S. Geological Survey Professional Paper 575-D, p. D176-D182.
Keith, Stanton B. (1975), Arizona Bureau of Mines Bull. 191, Index of Mining Properties in Santa Cruz County Arizona: 88 (Table 4).
Arizona Bureau of Mines file data.
A Pb-Ag-Cu-Zn-Au (Ba) mining area located in T.20-22S., R.15-16E. It adjoins the Tyndall District on the east, lying on the opposite or east slope of the southern part of the Santa Rita Mountains. It extends from the latitude of Old Baldy Peak on the north and Adobe Canyon on the northeast to Patagonia, 12 miles distant, on the south, and from the crest of the range between the Ariozona-Pittsburg and Augusta Mines to Sonoita Creek at the Pennsylvania Ranch, 8 miles distant, on the east. Its southeast boundary follows Sonoita Creek to a point 2¼ miles below Patagonia, where it meets the west boundary, which follows the ridge between Temporal Gulch on the east and Squaw Gulch on the west.
The surface declines across the west-central part of the district from an elevation of 6,500 to 4,500 feet in the distance of 6 miles. This is the part of the district in which most of the mines are located.
The country rock is mainly andesite, which occupies a north-south belt about 2½ miles wide in the west-central part of the district. In the northwest corner the andesite gives way to a belt of the underlying rhyolite ¾ mile wide, which extends 4 miles southward into the district and which on the south, along the middle of the west boundary, is succeeded by a similarly narrow belt of the quartz diorite and monzonite of the adjoining Tyndall district. This, in turn, along the southern part of the boundary, is similarly succeeded by the granite porphyry of Squaw Gulch, which also underlies the andesite on the east. Almost the whole of the eastern part of the district is covered by Quaternary gravels, through which, however, a small area of the Mesozoic shale protrudes on the north.
Mineralization is irregular groups and parallel bands of lensing quartz-fissure veins containing spotty base metal sulfides, pyrite and often barite, largely oxidized and enriched near the surface. The wall rocks are a banded belt of folded and faulted Mesozoic and Tertiary volcanics with interbedded sedimentary or tuffaceous members, Jurassic granite and quartz monzonite, and Laramide and Tertiary granodiorite stocks with rhyolite and quartz latite dikes.
Workings are numerous, scattered prospects and small mines worked since the late 1870's and up through the 1900's. Total estimated and recorded production for the district would be some 4,000 tons of ore containing about 475 tons of lead, 51,000 oz. of silver, 118 tons of copper, and 386 oz. of gold.
