New Mexico Mineral Symposium — Abstracts

Mining activity has been severely reduced recently in southwestern New Mexico due to a drop in copper values. Most operations have been shut down or greatly curtailed while waiting for a market upturn. However, precious metal prices have remained elevated, sparking recent activity in exploration and mining. Where there is mining, new mineral discoveries can be expected. And that is good news for mineral collectors. New mineral finds have recently been made as a result of mining activity and exploration as well as individual efforts by this author and others in southwestern New Mexico. Those will be addressed below.

Steeple Rock district, Grant County, New Mexico
Last year during the 2008 Mineral Symposium at New Mexico Tech, this author gave a talk on the mineral occurrences of the Steeple Rock district of western Grant County, New Mexico. Several developments concerning mining make this district encouraging for mineral collectors. First, the Summit Gold mine continues in operation. A 15% decline has been driven to intercept the Summit vein from the east. Ore is hauled by truck to a mill in the Lordsburg district for processing. Second, the Billali mine, which includes the Hoover tunnel, located in the north portion of the district, has been core drilled in the past and now is being developed for gold production. Third, a new gold orebody has been discovered at the Jim Crow mine in the southern part of the district. Even though this orebody is small, plans are underway for production. This orebody has already produced some interesting minerals: Duftite, epitactic vanadinite along with mimetite, gold, and pyromorphite are notable.

Lordsburg district, Hidalgo County, New Mexico
Recent field exploration in the Lordsburg district has resulted in discovery of a large porphyry copper/gold deposit. This district in the past has produced numerous collectable minerals. Only those "new" mineral finds are listed below.

Georgtown district, Grant County, New Mexico
Even easily accessible and well-visited districts continue to produce mineral specimens. The McGregor mine at Georgetown recently produced collectable wulfenite and bromargyrite from dump material. However, that was brought to an abrupt halt when a new home and commercial cabins were constructed over the collecting area. However, another area near the Georgetown Cemetery has produced an interesting suite of collectable minerals. This site, hiding in rather plain sight, in full view from the Georgetown Road, is the Alhambra mine. It is located at the southwest corner of the cemetery and contains wulfenite, plattnerite, bromargyrite, vanadinite, cerussite, willemite, hemimorphite, and jarosite. The original shaft has been back-filled, but most of the dump remains. The Forgotten Group mine shaft, located 800 ft southeast of the Alhambra mine, recently produced plattnerite, rosasite, descloizite, willemite, and hemimorphite. The small Edith mine, located north of the cemetery and close to the south side of the main road to Georgetown site, has recently produced a limited amount of yellow-green bromargyrite.

References:

1. Flege, R. F., 1959, Geology of the Lordsburg Quadrangle, Hidalgo County, New Mexico: New Mexico Bureau of Mines and Mineral Resources, Bulletin 62, 36 pp.
2. Gibbs, R. B., 2008, Mines and minerals of the Georgetown district, Grant County, New Mexico: Rocks & Minerals, v. 83, no. 1, pp. 34-43.
3. Gillerman, E. 1964, Mineral Deposits of Western Grant County, New Mexico: New Mexico Bureau of Mines and Mineral Resources, Bulletin 83, 213 pp.
4. Griggs, R. L., and Wagner, H. C., 1966, Geology and ore deposits of the Steeple Rock mining district, Grant County, New Mexico: U.S. Geological Survey, Bulletin 1222-E, 20 pp.
5. Northrop, S. A., 1996, Minerals of New Mexico, 3rd ed., revised by F. A. LaBruzza: University of New Mexico Press, Albuquerque, 346 pp.
6. Walstrom, R. E., 2008, Micromineral occurrences, Steeple Rock district, Summit Mountains, Grant County, New Mexico (abs.): New Mexico Geology, v. 30, no. 4, pp. 117-118.