Allison Mine (Fresnel Mine; Chance Mine; El Oro Mine; Old Gold Mine; Fourth of July vein; Roberts vein), Fresnel Canyon, Baboquivari Mining District, Baboquivari Mountains, Pima County, Arizona, USAi

Regional Level Types
Allison Mine (Fresnel Mine; Chance Mine; El Oro Mine; Old Gold Mine; Fourth of July vein; Roberts vein)	Mine
Fresnel Canyon	Canyon
Baboquivari Mining District	Mining District
Baboquivari Mountains	Mountain Range
Pima County	County
Arizona	State
USA	Country

Ref.: Worcester, A.W. (1931) Allison mine of El Oro Mining Company: Mining Journal: 15(3): 5-6.

Wilson, E.D., Cunningham, J.B., and Butler, G.M. (1934), Arizona Lode Gold Mines and Gold Mining (revised 1967), Arizona Bureau of Mines Bull. 137: 179-180.

Fair, C.L. (1965) Geology of the Fresnal Canyon area, Baboquivari Mountains, Pima County, Arizona: Tucson, University of Arizona, Ph.D. dissertation, 89 p.

Keith, Stanton B. (1974), Arizona Bureau of Geology & Mineral Technology, Geological Survey Branch Bull. 189, Index of Mining Properties in Pima County, Arizona: 107 (Table 4).

Lundin, R.J. (1976 ) Wallaby Enterprises Mining District Data Base – Baboquivari District.

Elevatorski, E.A. (1978), Arizona Industrial Minerals, Arizona Department of Mineral Resources, Minerals Report No. 2: 52.

Phillips, K.A. (1987), Arizona Industrial Minerals, 2nd. Edition, Arizona Department of Mines & Minerals Mineral Report 4, 185 pp.

Nowlan, G.A., Haxel, G.B., Hanna, W.F., Pitkin, J.A., Diveley-White, D.V., McDonnell, J.R., Jr., and Lundby, W. (1989) Mineral resources of the Baboquivari Peak and Coyote Mountains Wilderness Study Areas, Pima County, Arizona, Chapter E, in Mineral resources of Wilderness Study Areas: Southwestern and south-central Arizona: U.S. Geological Survey Bulletin 1702-E, p. E1-E30.

Peirce, H. Wesley (1990), Arizona Geological Survey Industrial Minerals card file.

Arizona Bureau of Mines file data.

MRDS database Dep. ID file #10039550, MRDS ID #M050259; and, Dep. ID #10113496, MAS ID #0040190725; and, Dep. ID #10259556, MAS ID #0040190095.

A former small underground Au-Ag-Cu-Pb-Mn-Silica mine on 20 unpatented claims. Located in the center-western ½ of sec. 33, T.18S., R.7E. (protracted), in the western Baboquivari Mountains, about 45 miles SW of Tucson. Discovered 1888 by Ricks and Burse. Owned at times, or in part, by Allison Brothers & Wicks; Allison Gold Mining Co.; Tom Reed Gold Mines Co. (leased the property in 1926); El Oro Mining & Milling Co. (1930- ); Tombstone Mining Co. of Arizona; Gold Bar Mining Co.; and the Old Gold Mining Co. NOTE: Additional names which apply to this property are: Fourth of July group; and the Fourth of July Nos. 2-4.

Mineralization is acanthite, silver and gold chlorides, native gold and minor copper and lead minerals in quartz lenses with gouge and abundant manganese and iron oxides along fault zones cutting tilted, metamorphosed, Tertiary conglomerate and sedimentary breccia beds with associated rhyolite and andesite porphyry dikes. The deposit is the Allison vein, that strikes eastward and is about 30 inches (0.8 meters) in maximum width. The quartz is grayish-white to olive-gray. The vein, as a whole, is rather low-grade but certain portions contain abundant manganese and iron oxides that were relatively rich in gold and silver. Side veins include the 4th of July and the Roberts, which are both near vertical.

Local rock is tilted conglomerate beds, intruded by dikes of rhyolite andesite porphyry. These beds form a broad foothill belt and contain numerous thin stringers of gold-bbearing quartz, locally associated with pyrite. The host rock unit is the Yellowstone Wash Formation.

Local structures include the Allison Fault Zone that strikes N30W and dips 75-80W.

Started about 1898. Workings include an old shaft and tunnel under the shaft (1923); a 320 foot adit and a 625 foot inclined shaft and extensive underground workings. There were 3 levels at 400, 525, and 625 foot levels; with a tunnel at the 200 foot level, and drifts, raises and winzes between levels. The best ore was at the 400 & 525 levels. Several thousand feet of underground workings in total. This mine produced intermittently from the 1890's through 1961. Reopened and active during the period 1923-1931. Work from 1955 to 1961 was on the side veins east of the Allison vein workings. Total estimated and recorded production was over 47,000 tons of ore averaging about 0.22 oz. Au/T, 2.7 oz. Ag/T, and minor lead and copper (2,176 oz. Au & 44,705 oz. Ag (1926-1928); $ 5,500 in Au-Ag bullion (period values), plus a few tons lof concentrates (1931).

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Link to USGS MRDS:	10039550

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