| Basis for focus area |
Cretaceous alkalic pluton (~98 Ma) is locally strongly altered and mineralized (Au, Ag, As, Mo, W). |
| Identified resources |
Historical production of copperas (iron sulfide) for tanning. |
| Production |
Unknown. |
| Status |
Past mining. |
| Estimated resources |
Unknown. |
| Geologic maps |
Ratcliffe and others (2011), scale 1;100,000; Burton and Ratcliffe (2000), scale 1:24,000. |
| Geophysical data |
Inadequate aeromagnetic and aeroradiometric coverage. |
| Favorable rocks and structures |
Cretaceous syenite stocks; White Mountain Plutonic Series. |
| Deposits |
Copperas Hill mine (MRDS dep_id: 10100274). |
| Evidence from mineral occurrences |
MRDS. |
| Geochemical evidence |
Ore at Copperas Hill mine was 40% Fe, 25% S, 3.5% Mn, 0.2% Zn, 0.2% Cu, 0.4 oz/t Au and 0.03 oz/t Ag (Slack, 1990). |
| Geophysical evidence |
Magnetic and gravity data in Daniels (1990). |
| Evidence from other sources |
Unknown. |
| Cover thickness and description |
Exposed bedrock or glacial till and lacustrine deposits generally less than 10-50 m. |
| Authors |
Gregory J. Walsh, Gilpin R. Robinson, Jr. |
| New data needs |
Mapping. |
| Geologic mapping and modeling needs |
1:24,000 scale mapping is available in USGS preliminary open-file report format, but could be updated (Burton and Ratcliffe, 2000). |
| Geophysical survey and modeling needs |
High resolution aeromagnetic and aeroradiometric coverage to image mafic rock, associated structures, and alteration. Electromagnetic methods may help image sulfides. |
| Digital elevation data needs |
Lidar adequate. |
