Twin Cedars, Big Bertha, South Platte pegmatites

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 Buffer around point from Foley, Jaskula, Piatak and Schulte (2017). Area encloses the South Platte pegmatite district. Buffer encloses a few fluorspar records outside of the South Platte district.
Identified resources Historical production of feldspar, fluorite, and quartz.
Production Unknown.
Status Past mining.
Estimated resources Unknown.
Geologic maps Peterson (1964), scale 1:24,000; Ruleman and others (2011), scale 1:100,000.
Geophysical data Inadequate Rank 5 aeromagnetic and Rank 3 aeroradiometric coverage.
Favorable rocks and structures Pegmatites in Buffalo Park intrusive center (northern portion of the Pikes Peak granite).
Deposits Butte 1, Dazie Bell mine (MRDS dep_id: 10013724), Delbert Claims #1&2, Gilpin #1, Little Patsy #1&2, Luster Lode claim (fluorite past producers).
Evidence from mineral occurrences MRDS.
Geochemical evidence MINDAT lists more than 50 pegmatite localities in the district; numerous REE and Nb-Ta minerals. Some geochemical data published by Simmons and others (1987). Gagnon and others (2004) suggest low temperature (90-110 °C) F-bearing fluids mixed with Ca released during albitization and associated replacement alteration of primary pegmatite.
Geophysical evidence Unknown.
Evidence from other sources Unknown.
Comments Proterozoic pegmatites in the Pikes Peak batholith. Also note that this area overlaps with the South Platte focus area.
Cover thickness and description No cover.
Authors Ryan D. Taylor, Jane M. Hammarstrom, Joshua M. Rosera, V.J.S. (Tien) Grauch, David A. Ponce.
New data needs 1:24,000 scale geologic mapping and potential geochemical sampling.
Geologic mapping and modeling needs 1:24,000 scale geologic mapping of the Deckers quadrangle.
Geophysical survey and modeling needs Detailed aeromagnetic and aeroradiometric could help distinguish different petrologic types on the ground, but would not be good at detecting pegmatites themselves.
Digital elevation data needs Lidar complete on southern half of focus area; in progress on northern half.