Eight Mile Park district

Region West, Rocky Mountains
Mineral systems
Deposit types
Critical minerals
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Proterozoic-age pegmatites may not be associated with Climax-type deposits at depth. Pegmatite district covers about 10 square miles west of Canon City. General area based on MRDS producers and past producers.
Identified resources Identified beryllium (beryl) resources. Historical production of beryllium (beryl), feldspar, mica, niobium (columbite), and tantalum (tantalite).
Production Mica Lode produced 152,180 mt feldspar, 31,230 mt scrap mica, and 51 mt of beryl. The Mica Lode mine also produced 615 lbs of columbite-tantalite (Schwochow and Hornbaker, 1985). Meyer's and School Section mines produced ~ 1 t of beryl.
Status Past mining (mostly beryl). Areas near and within this focus area are currently being explored for other commodities within a stratabound deposit at depth, including Zn, Cu, Pb, Ag, and Au.
Estimated resources Mica Lode mine: 100 mt beryl inferred (1950; visual estimate). Hanley and others (1950) suggest that reserves are 2 or 3 times this estimate.
Geologic maps Taylor and others (1975), scale 1:62,500; Raymond and Sheridan (1980), scale 1:79,000; Scott and others (1978), scale 1:250,000.
Geophysical data Inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Pegmatite.
Deposits Mica Lode mine (MRDS dep_id: 10013530), Meyers mine, School Section mine, Border feldspar prospect, Colfelco No. 12 pegmatite, Consolidated Feldspar Corp, Devil's Hole quarry, Lorain pegmatite, RH Magnuson.
Evidence from mineral occurrences MRDS.
Geochemical evidence Pegmatite exposed at the surface.
Geophysical evidence No data.
Evidence from other sources No data.
Comments Mica Lode mine: low-grade but high-tonnage beryl deposit (Hanley and others, 1950). Scandium inferred from the mineral system/deposit type table (Hofstra and Kreiner, 2020).
Cover thickness and description Pegmatite exposed at the surface.
Authors Ryan D. Taylor, Joshua M. Rosera, V.J.S. (Tien) Grauch, Michael K. O'Keeffe.
New data needs 1:24,000 scale geologic mapping.
Geologic mapping and modeling needs Need 1:24,000 scale geologic mapping for the Royal Gorge, Gribble Mountain, Rice Mountain, McIntyre Hills, Echo, Hillside, and Iron Mountain quadrangles. 1:65,000 scale reconnaissance geologic mapping exists for this area. Colorado Geological Survey is currently working on a 1:50,000 scale compilation geologic map of this area.
Geophysical survey and modeling needs High resolution Rank 1 aeromagnetic and aeroradiometric survey may not work well with this deposit type, except if help is needed in geologic mapping of different petrologic characteristics.
Digital elevation data needs Lidar adequate.