| Basis for focus area |
MRDS producer and past producers. |
| Identified resources |
Estimated reserves of beryllium (beryl), feldspar, muscovite, and niobium (columbite). Historical production of beryllium (beryl), feldspar, scrap mica, and niobium-tantalum (columbite-tantalite). |
| Production |
Production during the 1930s included 200 tons of feldspar, 150 tons of scrap mica, 25 ton of beryl, and 1 ton columbite-tantalite. |
| Status |
Past mining. |
| Estimated resources |
Reserves are difficult to estimate as the percentages of muscovite, feldspar, beryl, and columbite varies and character at depth is unknown; an estimated 7,500 tons of rock contains about 1,900 tons muscovite, 38 to 150 tons of beryl, and 15 to 30 tons columbite (Hanley and others, 1950). |
| Geologic maps |
Temple and Busacca (2009), scale 1:24,000. |
| Geophysical data |
Inadequate Rank 5 aeromagnetic and Rank 3 aeroradiometric coverage. |
| Favorable rocks and structures |
The Meyers Ranch pegmatite intrudes fine- to coarse-grained red granite gneiss of Precambrian age. |
| Deposits |
Meyers Ranch (MRDS dep_id: 10013023). |
| Evidence from mineral occurrences |
MRDS. |
| Geochemical evidence |
No data. |
| Geophysical evidence |
No data. |
| Evidence from other sources |
No data. |
| Cover thickness and description |
Exposed at the surface; depth unknown. |
| Authors |
David A. Ponce, Nora K. Foley, Michael K. O'Keeffe. |
| New data needs |
1:24,000 scale geologic mapping. |
| Geologic mapping and modeling needs |
1:24,000 scale geologic mapping at the Thirtynine Mile Mountain quadrangle. |
| Geophysical survey and modeling needs |
High resolution, Rank 1 aeromagnetic and radiometric surveys. |
| Digital elevation data needs |
Lidar adequate. |
