| Basis for focus area |
The two Tallahassee Creek focus areas include identified occurrences and the spatial extent of the associated host Tallahassee Creek Conglomerate and Echo Park Alluvium. Mineralization is above horst structures associated with carbonaceous material, pyrite, carbonate and secondary silica in sandstones and conglomerates interbedded with the Wall Mountain Tuff (Chenoweth, 1980; Sanford, 1992). Area is adjacent and overlaps with the Guffey mining district/area which includes numerous types of deposits with critical minerals not listed here. Area overlaps with the northern portion of the Wet Mountains. |
| Identified resources |
Indicated resources and historical production of uranium. |
| Production |
Between 1957 and 1972 95,400 tons of ore averaging 0.25% U3O8 were mined, mostly form the Tallahassee Creek Conglomerate (Chenoweth, 1980). Between 1954 and 1972, a total of about 225,000 kg U3O8, at grades between 0.2 to 0.3%, was produced from the mines in this area (Hon, 1984). |
| Status |
Past mining. Recent exploration by Black Range Minerals now owned by Western Uranium and Vanadium Corporation as of 2015. |
| Estimated resources |
60 million lbs of U3O8 Indicated and Inferred resource for the Taylor Ranch deposit using a 0.25% U3O8 cutoff grade; 10 million lbs of U3O8 Indicated and Inferred using a 0.075% cut-off grade (Black Range Minerals Ltd., 2009). Western Uranium and Vanadium (previously Western Uranium) reports that the historical Hansen/Taylor district has resources of 29,730,000 tons grading at 0.063% U3O8 containing 37,480,000 lbs U3O8 and an Inferred U resource of 43,681,000 tons with a grade of 0.058% U3O8, containing 50,443,000 lbs U3O8 (Western Uranium, 2017). The Hansen deposit is in the Echo Park Alluvium and contains about 12 million kg of U3O8 and the Picnic Tree is in the Tallahassee Creek Conglomerate and contains about 1 million kg of U3O8 (Dickinson, 1981). Average grade of both deposits is about 0.08% U3O8 (Dickinson, 1981). Additional ore grades, reserves, and production for smaller deposits are summarized in Hon (1984). |
| Geologic maps |
Horton and others (2017), scale 1:500,000. |
| Geophysical data |
Inadequate aeromagnetic and aeroradiometric coverage. |
| Favorable rocks and structures |
Oligocene Tallahassee Creek Conglomerate and Eocene Echo Park Alluvium. Basement horst blocks are related to U mineralization (Sanford, 1992). |
| Deposits |
Tallahassee Creek district (MRDS dep_id: 10107981), Hansen, Taylor Ranch, Picnic Tree, Boyer, Noah, James-Taylor, First Chance, Misery mine Group, Dickson-Snooper, Knob Hill, Cap Rock Claims, Gunnison School Section mine, Joan 2 mine, Little Abner mine, Mary L, Glen Williams mine, Sunshine Claims, Thome Claims. |
| Evidence from mineral occurrences |
MRDS; International Atomic Energy Agency (2020b); U.S. Environmental Protection Agency (2006); numerous past producers (Nelson-Moore and others, 1978). |
| Geochemical evidence |
No data. |
| Geophysical evidence |
Unknown. |
| Evidence from other sources |
Both U focus areas were explored between 2009 and 2011. The companies that were active in the area were Buckingham Exploration Inc., Black Range Minerals and Uranium One. |
| Comments |
The Colorado Geological Survey (CGS) has unpublished data from this area that was recently cataloged but has not been made available publicly. CGS personnel are very familiar with these geological units and have been mapping quadrangles in this area for a decade. |
| Cover thickness and description |
The Hansen/Taylor Ranch deposit is between 150 and 190 meters below the surface. |
| Authors |
Susan Hall, Michael K. O'Keeffe. |
| New data needs |
Make unpublished Colorado Geological Survey data available, 1:24,000 scale geologic mapping, geophysical survey. |
| Geologic mapping and modeling needs |
Dicks Peak, Black Mountain, Gribble Mountain, Hall Gulch, Waugh Mountain, Thirtyone Mile Mountain, Echo, Cripple Creek South, and High Park quadrangles need 1:24,000 scale mapping. The Colorado Geological Survey is currently mapping the Guffey Northwest quadrangle under the STATEMAP program. Other areas without recorded radioactive mineral occurrences but contain large outcrops of Echo Park alluvium and/or Tallahassee Creek Conglomerate include the Lake George and Wrights Reservoir 1:24,000 quadrangles, which are not mapped. |
| Geophysical survey and modeling needs |
Rank 1 aeromagnetic/aeroradiometric data is needed. EM data would also be very helpful. |
| Digital elevation data needs |
Lidar is adequate. |
