| Basis for focus area |
Radioactive (U- and Th-rich) paraconglomerates (Early Proterozoic Magnolia Formation of the Deep Lake Group/Snowy Pass Supergroup and the Archean Deep Gulch conglomerate of the Phantom Lake Metamorphic Suite) exist within the focus area. Possibility of placer deposits derived from other systems and deposit types in the Sierra Madre. |
| Identified resources |
Identified resources for uranium. |
| Production |
Unknown. |
| Status |
From Hausel (1986): "During the late 1970s and early 1980s, several uranium companies and some precious-metal companies prospected the [Sierra Madres paleoplacer] district. |
| Estimated resources |
From Hausel (1986): "Resources estimated from scattered drilling and outcrop sampling are 3,860 tons of U3O8 at a cutoff grade of 100 parts per million (ppm) U3O8, and 8,350 tons of ThO2 at a cut-off grade of 100 ppm ThO2... |
| Geologic maps |
Houston and Graff (1995), scale 1:50,000; Sutherland and Hausel (2004), scale 1:100,000. |
| Geophysical data |
Inadequate aeromagnetic and aeroradiometric coverage, poor ground gravity coverage. |
| Favorable rocks and structures |
Precambrian quartz-pebble conglomerate paleoplacers. Uranium and Th in the Early Proterozoic Magnolia Formation of the Deep Lake Group/Snowy Pass Supergroup and the Archean Deep Gulch conglomerate of the Phantom Lake Metamorphic Suite. |
| Deposits |
Kings Claims (MRDS dep_id: 10018834), unknown prospect (MRDS dep_id: 10254551). |
| Evidence from mineral occurrences |
MRDS. |
| Geochemical evidence |
From Houston, Karlstrom and Graff (1978): elevated radioactivity vs background and U/Th ppm levels in Sierra Madre samples. |
| Geophysical evidence |
No data. |
| Evidence from other sources |
No data. |
| Cover thickness and description |
Variable, mix of good exposure to abundant surficial cover and heavily forested areas. |
| Authors |
Rachel N. Toner, Patricia M. Webber, Benjamin J. Drenth, Michael L. Zientek, Robert W. Gregory, Kevin Mosser. |
| New data needs |
1:24,000 scale geologic mapping supported by high-quality geophysics and lidar, especially along trace of Cheyenne Belt; new reconnaissance geochemistry. |
| Geologic mapping and modeling needs |
1:24,000 scale geologic mapping of the igneous and metamorphic stratigraphy, structural and deformation features (especially along Cheyenne Belt), and mineralization trends with precise ground control is essential. Requires outcrop-level mapping. |
| Geophysical survey and modeling needs |
Rank 1 aeromagnetics and radiometrics, also a major ground gravity campaign. |
| Digital elevation data needs |
Lidar in progress with small areas complete. |
