| Basis for focus area |
Focus area around Monte Cristo mine in the Constellation area of the Black Rock mining district in Yavapai County, Arizona. |
| Identified resources |
Historical production of native silver. |
| Production |
Unknown. |
| Status |
Past mining. |
| Estimated resources |
Unknown. |
| Geologic maps |
Arizona Bureau of Mines (1958), scale 1:375,000. |
| Geophysical data |
Inadequate Rank 4 aeromagnetic coverage. |
| Favorable rocks and structures |
High-angle quartz veins, associated with rhyolite or andesite dikes of probable Mid-Tertiary age, that cut Precambrian granitic gneiss. |
| Deposits |
Monte Cristo mine (MRDS dep_id: 10027541). |
| Evidence from mineral occurrences |
MRDS. |
| Geochemical evidence |
From Bastin (1922): Silver occurs as the native metal, often with niccolite (nickeline, a Ni-arsenide) and more rarely with chloanthite (a Ni-arsenide isomorphous with skutterudite). Two generations of ores include: 1) arsenopyrite, pyrite, chalcopyrite, and quartz, and 2) proustite, tennantite, and calcite, with minor amounts of chalcopyrite, gersdorffite, argentite, pearceite (ruby silver), and quartz. |
| Geophysical evidence |
Unknown. |
| Evidence from other sources |
Past exploration. |
| Comments |
Bastin (1922) stated that the Monte Cristo ores conclusively showed that native Ag occurred as a primary associate of Ni and Co arsenides. |
| Cover thickness and description |
Veins exposed at the surface; best silver values at depth. |
| Authors |
Laurel G. Woodruff. |
| New data needs |
Updated geologic mapping, lidar, geochemistry, aeromagnetic and aeroradiometric surveys. |
| Geologic mapping and modeling needs |
Updated geologic mapping. |
| Geophysical survey and modeling needs |
High-resolution, Rank 1 aeromagnetic and aeroradiometric surveys. |
| Digital elevation data needs |
Lidar inadequate. |
