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. |