| Basis for focus area |
Polygons modified from the National Assessment tract CR24 ((U.S. Geological Survey National Mineral Resource Assessment Team, 2002), previously categorized as Massive sulfide, Kuroko-type. Permissive tracts were limited to areas with documented Precambrian disseminated to massive sulfide mineralization (Sheridan and Raymond, 1984). Many of these occurrences are gahnite-bearing and associated with metavolcanic or metasediment rocks. |
| Identified resources |
Historical production of copper and zinc. |
| Production |
Sedalia deposit near Salida, Colorado produced nearly 100,000 metric tons of Cu-Zn ore. |
| Status |
Past mining. |
| Estimated resources |
Unknown. |
| Geologic maps |
Scott and others (1978), scale 1:250,000; Tweto, Steven and others (1976), scale 1:250,000. |
| Geophysical data |
Inadequate aeromagnetic and aeroradiometric coverage. |
| Favorable rocks and structures |
Precambrian metavolcanic and metasedimentary rock. |
| Deposits |
Sedalia deposit (MRDS dep_id: 10013834). |
| Evidence from mineral occurrences |
MRDS; Other occurrences documented in Sheridan and Raymond (1984). |
| Geochemical evidence |
Disseminated to massive gahnite and sphalerite as well as other base metal minerals. |
| Geophysical evidence |
No data. |
| Evidence from other sources |
No data. |
| Comments |
Gahnite (Zn-spinel) replaces sphalerite in documented deposits and occurrences. Presence of gahnite is considered to be an indicator for these deposits in the region (Sheridan and Raymond, 1984). |
| Cover thickness and description |
Variable, mix of good exposure to thick surficial cover. |
| Authors |
Allen K. Andersen, Deborah A. Briggs, Joshua M. Rosera. |
| New data needs |
Geologic mapping, lidar, geochemical sampling of ore (if available), host rock, and waste piles for critical minerals. |
| Geologic mapping and modeling needs |
None requested at this time. |
| Geophysical survey and modeling needs |
None requested at this time. |
| Digital elevation data needs |
Lidar inadequate. |
