Quartz Ledge Mine (Porcupine Mine; White Cow Mine), Jakes Corner area, Tonto Basin, Tonto Basin District, Gila Co., Arizona, USA

• Display
  • Standard
  • Detailed
  • By Strunz Category
  • By Dana Category
• Photos
  • Add Photo
• Maps
  • Map Pages
  • Nearest Localities
• Search
  • Mineral Search
  • Search Google
  • Link to USGS

A former surface and underground fluorspar-Ag-Au mine located in the NE¼NE¼NE¼ sec. 20, T7N, R11E, about 5 miles SSE of Jakes Corner, on National Forest land. Produced 1971-1973. Owned and operated by Pro-Met of Arizona, Inc. of Arizona (1982).

The acquisition cost of $1,000,000 was paid by Pro-Met in November, 1980 for the Quartz Ledge, Red Rock, Bluebird, and the mill. 1/3 of this value ($333,000) was credited to the Quartz Ledge - $163,000 for acquisition cost of the deposit and $170,000 for the Quartz Ledge share of the mill capital cost. The mill capital cost is $170,000, which is the Quartz Ledge share of cost in November 1980. The actual cost of constructing the mill in 1971 was $600,000. Mill operating cost based on actual operating cost of $10/st in 1979 converted to metric and updated to July 1981.

Mineralization is a vein type fluorspar deposit with a tabular-shaped orebody. The ore zone is 214 meters long, 15 meters wide, with a depth-to-top of 15 meters, and a thickness of 1.5 meters, striking N45W, and dipping 75S. Ore is controlled by a shear zone.

The district is also underlain by Precambrian granite, with younger Precambrian Apache Group overlaying it. Cretaceous granite intrudes older rocks. There are 2 veins: South (principal) vein N45W, dip 75SW, 214M lenght X 15m depth X 1.5m thickness; North vein N40W, dip 85SW, 91m length X 15m depth X 1m thickness.

Workings are 500 meters in length and 18 meters in depth. Mining was accomplished by the shrinkage method. The deposit was evaluated for fluorspar only. According to the owner, some gold and silver values have been found, but no assays or reserve figures were made available. Most sources report that this property has little, if any, reserves, and is not worth investing in.

Surface geologic mapping has been done for Gila County (Arizona Bureau of Mines 1959). The test adit is a 15 degree incline 20 meters deep, and is currently flooded. The test pit is 305 meters long X 6 meters wide X 4.6-6 meters deep, and obscures much of the surface geology. Other method includes some sampling by the current owner, no assays were made available for this evaluation. The only production was 270 MT of development ore (1971-1973) from the incline and test pit, no production since then.

There are no published reserves for this deposit, Q-MAT1 COL1 is the reserve figure used for this evaluation - 19,800 MT at 50% CaF2. Two other unpublished USBM reports put reserves at 816 MT, grade 45% (Wood 1/24/75), and 4536-9072 MT, grade 40-50% CaF2 (Stewart 1957).

References

Stewart, L.A. (1957) U.S. Bureau of Mines Review of Examination, Quartz Ledge (Porcupine), July 24, 1957, 3 pp.

Mieritz, R.E. (1958) Tonto Basin Fluorspar District: Report to the Transworld Mining Syndicate, March 13, 1958, 6 pp.

Van Alstine, R.E. and Moore, R.T. (1969) Fluorspar, in Arizona Bureau of Mines Bull. 180 (USGS Bull. 871): 353.

Wood, H.B. (1974) Memorandum on Fluorspar Activity and reserve Files, Red Rock and White Cow Mines. U.S. Bureau of mines files, Jan 24, 1974.

Minerals Availability System: Arizona Fluorspar, Arizona Department of Mineral Resources, Grant No. G0254012, March 1976.

Morse, D. E. (1980) Mineral Facts and Problems, Fluorine Chapter. U.S. Bureau of Mines Bull. 671: 303-321.

Peirce, H.W. (1990), Arizona Geological Survey Industrial Mineral card files.

USGS, Picture Mountain 7.5 minute topo map.

Arizona Department of Mineral Resources White Cow Mine file.

Arizona Department of Mineral Resources Geology File Tonto Basin Fluorspar District: 4.

MRDS database Dep. ID #10209714, MAS ID #0040070006.

Mineral List

Fluorite

Quartz

2 entries listed. 2 valid minerals.