| Basis for focus area |
Cretaceous quartz monzonite hosts multiple U occurrences (Dahl, Daybreak, Curtin, Morning Sun and others; Huntting, 1957). Limited production is reported from the Dahl mine (Pool, 2017). The focus area was delineated based on host Cretaceous granite and related U occurrences. |
| Identified resources |
Historical production of uranium. |
| Production |
Dahl mine (1955-1966): 80,000 lbs of U3O8 (Pool, 2017). |
| Status |
Past mining. |
| Estimated resources |
Unknown. |
| Geologic maps |
Weissenborn and Weis (1976), scale 1:62,500; Stoffel and others (1991), scale 1:250,000. |
| Geophysical data |
Rank 2 aeromagnetics on western side of focus area (see Blakely and others, 2015); Rank 3 on eastern side; no aeroradiometric data. |
| Favorable rocks and structures |
Veins/shear zones in Cretaceous granite. |
| Deposits |
Dahl mine (MRDS dep_id: 10056123). |
| Evidence from mineral occurrences |
MRDS; International Atomic Energy Agency (2020b); U.S. Environmental Protection Agency (2006). |
| Geochemical evidence |
Unknown. |
| Geophysical evidence |
Unknown. |
| Evidence from other sources |
Multiple uranium occurrences (Daybreak Mine, Morning Sun, Huffman Lease and others) cluster within the Cretaceous intrusive rock in comprising the Mount Spokane Uranium Area. |
| Comments |
Focus area listed as a Magmatic REE-Peralkaline syenite/ granite/rhyolite/alaskite/pegmatite. Only known mineralization is uranium. Enrichment of all other critical commodities listed has been inferred from the mineral system/deposit type table (Hofstra and Kreiner, 2020). |
| Cover thickness and description |
Exposed at the surface. |
| Authors |
Susan Hall, Joshua M. Rosera. |
| New data needs |
Geophysics, mapping, and geochemistry. |
| Geologic mapping and modeling needs |
Detailed mapping and geochemistry. |
| Geophysical survey and modeling needs |
High-resolution, Rank 1 aeromagnetic and aeroradiometric coverage. |
| Digital elevation data needs |
Lidar complete (QL3). |
