Conglomerate Mine (Anderson Mine; Snyder Mine; Silver Moon; Sonoita; Reese; Colossa; Aurum; A.W.A.; Anderson prospect), Fish Canyon, Greaterville, Greaterville District, Santa Rita Mts, Pima Co., Arizona, USA

‡Ref.: Schrader, F.C. & J.M. Hill (1915), Mineral deposits of the Santa Rita and Patagonia Mountains, Arizona, USGS Bull. 582: 153, 154.

Elsing, M.J. and Heineman, E.S. (1936) Arizona Metal Production, Arizona Bureau of Mines Bulletin 140.

Drewes, H.D. (1971) Geologic map of the Mount Wrightson quadrangle, southeast of Tucson, Santa Cruz and Pima Counties, Arizona: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-614 (Mt. Wrightson Quadrangle), 1 sheet, scale 1:48,000.

Keith, Stanton B. (1974), Arizona Bureau of Geology & Mineral Technology, Geological Survey Branch Bull. 189, Index of Mining Properties in Pima County, Arizona: 120 (Table 4).

USGS Mt Wrightson 7.5 minute Quadrangle topo map.

Arizona Bureau of Mines file data.

MRDS database Dep. ID file #10039599, MRDS ID #M050402; and, Dep. ID #10109818, MRDS ID #M800069; and, Dep. ID #10159323, MAS ID #0040190167.

A former small underground Ag-Au-Cu-Pb mine located in South-central (SW¼SE¼) sec. 36, T.19S., R.15E., near the top of the limestone ridge on the south side of Fish Canyon, 2½ miles SSW of Greaterville, 50 to 200 yards north of the Santa Cruz County line, at 5,640 feet of altitude. Discovered 1915 by J.E. Anderson. Operated 1909-1955. Closed by February 1936 and reopened at an unknown later date. Owned by J.E. Anderson; the Midland Copper Co.; Phelps Dodge Corp.; the Snyder Mining & Milling Co. (1955)p; and, Mr. Phil Snyder (owner-operator) (1976).

Claims and prospects on the Snyder Mine property extend to the south into Santa Cruz Co. and, in the past, this mine has also been recorded in that county. The main mine and workings are in Pima Co. and all records are now (1994) recorded here.

Mineralization is a shear zone, hydrothermal deposit with an irregular and lensing quartz vein with partially oxidized lead and copper minerals in a strongly brecciated and silicified fault zone striking NW-SE along a contact of Precambrian granite (1450 ± 10my) and Paleozoic limestone. The host rock unit is the Epitath Dolomite (Upper Member).

Ore minerals are sulfides, carbonates and halides occurring in pockets and small boulders scattered through the zone. Miocene Tertiary quartz latite dikes occur throughout the district and may be strongly related to mineralization. Plugs and dikes are associated with mineralization 1 mile north at the Comstock Mine. Alteration includes oxidation, silicification, and brecciation. Oxidation extends to the bottom of the 50 foot shaft but starts decreasing below the 20 foot level.

Local structures include regional tilting and broad open folds in the south, and extensive faulting in the north. Thrust and normal faulting - shear zones; block faulting.

Workings include a 500 foot deep shaft (circa 1915) and tunnel operations. Anderson reported production prior to 1915, the U.S. Bureau of Mines data begins in 1925. First produced in 1909 or earlier, then worked by Phelps Dodge in the 1920'S. It was the largest producer in the Greaterville District, other than placers. Worked sporadically from the early 1900's to 1955, producing some 1,000 tons of ore averaging about 10% Pb, 8 oz. Ag/T and minor Cu & Au.