| Basis for focus area |
Basis for the focus area is a syenite porphyry laccolith and intrusive breccia pipes and dikes within the laccolith. Possible skarn generation along the intrusion contacts with carbonate rocks. The presence of fluorite suggests the breccia pipes or syenite intrusion should be tested for REE, Nb, Ta and Te. The gold resources should be re-examined for a possible telluride resource. |
| Identified resources |
Historical production of gold and silver. |
| Production |
From 1987 to 1995 the Kendall mine produced 9 million tons of ore that yielded 300,000 oz Au and 135,000 oz Ag. |
| Status |
Past mining and exploration for Au resources in the 1970s and 1980s. Final reclamation at the Kendall mine began in 1995. |
| Estimated resources |
Unknown. |
| Geologic maps |
Porter and Wilde (1993), scale 1:100,000. |
| Geophysical data |
Inadequate aeromagnetic and aeroradiometric coverage. |
| Favorable rocks and structures |
Paleocene syenite porphyry laccolith followed by hydrothermal intrusive breccia pipes. Known deposit types are disseminated and stratabound gold deposits hosted by karst breccias. |
| Deposits |
Kendall mine (MRDS dep_id: 10269407). |
| Evidence from mineral occurrences |
MRDS. |
| Geochemical evidence |
Gold telluride minerals are reported to be present along with gangue fluorite. There is no known geochemical evidence for the occurrence of critical elements with the exceptions of: 1) Te, which is known to occur in the Au-Ag deposits, and 2) Zn, which occurs in sphalerite and/or smithsonite in a few areas. |
| Geophysical evidence |
None. |
| Evidence from other sources |
Breccia pipes hosted by the syenite porphyry with fluorite are known in other districts to host REE, Nb, and Ta. |
| Comments |
Even though critical elements were not produced, there is a possibility the syenite porphyry laccolith and associated hydrothermal breccias could be source for critical elements. |
| Cover thickness and description |
Partially exposed at the surface and extends to unknown depth. Ore found in an upper oxidized zone and a lower unoxidized zone. |
| Authors |
Stanley L. Korzeb, Kaleb C. Scarberry, Jay A. Gunderson, Joshua M. Rosera. |
| New data needs |
High resolution geophysics, whole-rock geochemistry for all critical minerals, geologic mapping, lidar. |
| Geologic mapping and modeling needs |
1:24,000 scale geologic mapping. |
| Geophysical survey and modeling needs |
High resolution aeromagnetic and aeroradiometric coverage. |
| Digital elevation data needs |
Lidar in progress. |
