Peloncillo Mountains (San Simon, McGhee Peak, Steins Pass districts)

Region West, Southwest
Mineral systems
Deposit types
Critical minerals
Other minerals

Information leading to the delineation of this focus area

Basis for focus area This focus area consists of carbonate-hosted, skarn, and epithermal deposits found in the San Simon, McGhee Peak, and Steins Pass districts in the central Peloncillo Mountains, New Mexico (McLemore, 2017).
Identified resources Historical production of antimony, manganese, and tungsten.
Production 3000 tons WO3 (1943, 1954-1957) from Steins Pass; 5 tons Sb, and minor Mn.
Status Past mining, recent exploration.
Estimated resources Unknown.
Geologic maps Gillerman (1958), scale 1:48,000; Armstrong, Silberman and others (1978), scale 1:24,000; Hoag (1991), scale 1:12,000; Drewes and Thorman (1980), scale 1:24,000.
Geophysical data Inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Southwest porphyry copper belt.
Deposits Ward (MRDS dep_id: 10009974), Granite Gap mines (MRDS dep_id: 10101434), McGhee Peak, Beck mine (MRDS dep_id: 10010039), Volcano mine (MRDS dep_id: 10101442).
Evidence from mineral occurrences MRDS; New Mexico Mines Database (McLemore and others, 2005).
Geochemical evidence Some of the highest As, Sb, Te, W, and Au values are found in the area in the reanalyzed NURE stream sediment samples.
Geophysical evidence Unknown.
Evidence from other sources New Mexico Mining and Minerals Division mine permits.
Comments Carbonate-hosted Pb-Zn replacement, skarn, and epithermal veins deposits are associated with Tertiary intrusions. Primary ore minerals are sphalerite, galena, and chalcopyrite with minor tetrahedrite in a gangue of quartz, calcite, pyrrhotite, barite, and pyrite. Bismuth occurs in arsenopyrite; and scheelite and molybdenite occur in some mines. Jasperoids are common but have not been sampled or mapped. Tungsten occurs with the base- and precious-metals locally and was shipped from the Ward (Baker-Standard) mine in the San Simon district. Some Mn was produced from the Black Face mine in the northern part of the San Simon district during WWII, where epithermal Mn veins occur in rhyolite porphyry. Drill core at NMBGMR.
Cover thickness and description Potential for buried or eroded deposits in fault-bounded basin.
Authors Virginia T. McLemore.
New data needs Geochemistry, regional geophysics.
Geologic mapping and modeling needs Detailed geology-structure-alteration-mineralization mapping.
Geophysical survey and modeling needs High resolution Rank 1 aeromagnetic and aeroradiometric coverage.
Digital elevation data needs Lidar complete.