Alum Mountain

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

Information leading to the delineation of this focus area

Basis for focus area Mining district outlines from McLemore (2017).
Identified resources Historical production of aluminum (alunite, kaolin), gold, and silver.
Production Possibly a few wagon loads of 'alum rock' shipped in 1890s for testing. In 1945, 3 short tons of ore were produced containing 1 oz/t Au and 21 oz/t Ag from volcanic epithermal vein deposits (McLemore and others, 1996).
Status Past mining (but now near Wilderness area).
Estimated resources Hall (1978) estimates 90 million tons of 20% alunite.
Geologic maps New Mexico Bureau of Geology and Mineral Resources (2003), scale 1:500,000.
Geophysical data Inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Acid-sulfate alteration, original host rhyolite.
Deposits Alum Mountain deposit (MRDS dep_id: 10009281).
Evidence from mineral occurrences MRDS.
Geochemical evidence Unknown.
Geophysical evidence None.
Evidence from other sources Unknown.
Comments These acid sulfate altered areas have been known because of their implications in porphyry Cu exploration. However, they are best modeled as paleo-geothermal systems (hot springs). Anomalous Au, Ga, and other elements are found in these areas. Detailed alteration mapping coupled with mineralogy and geochemistry are critical in understanding these systems and determine if they are potential resource for alunite (Al), Au, Ga, Ge, and other critical elements.
Cover thickness and description Exposed at the surface. Hills of this altered area are very distinct from other topographic feature in the region and are characterized by many pinnacles and isolated buttes.
Authors Virginia T. McLemore.
New data needs Detailed alteration mapping, chemistry, mineralogy.
Geologic mapping and modeling needs Alteration mapping.
Geophysical survey and modeling needs High resolution, Rank 1 aeromagnetic and aeroradiometric coverage.
Digital elevation data needs Lidar complete.