| Basis for focus area |
Focus area is based on historical coal mine locations from Carroll and Bauer (2002). Tetra Tech, Inc. (2015) reports that higher REE contents were noted east of the central Front Range and east of the Spanish Peaks volcanic complex. |
| Identified resources |
Historical production of coal. |
| Production |
Unknown. |
| Status |
Unknown. |
| Estimated resources |
Unknown. |
| Geologic maps |
Horton and others (2017), scale 1:500,000. |
| Geophysical data |
Inadequate aeromagnetic and aeroradiometric coverage. |
| Favorable rocks and structures |
Clays in coal seams throughout Colorado, especially kaolinite beds. |
| Deposits |
No data. |
| Evidence from mineral occurrences |
No data. |
| Geochemical evidence |
See DOE studies on REE in coal, especially Tetra Tech, Inc. (2015). |
| Geophysical evidence |
No data. |
| Evidence from other sources |
No data. |
| Comments |
Area could include the entire coal basin however, in order to minimize the size of the focus area, polygons were created to capture the location of historical coal mines. |
| Cover thickness and description |
Outcrop and subcrop. |
| Authors |
Michael K. O'Keeffe. |
| New data needs |
Mostly geochemical sampling of clay seams in outcrops for REE. |
| Geologic mapping and modeling needs |
Geochemical sampling of clay seams in coal based on Tetra Tech, Inc. (2015) DOE study. |
| Geophysical survey and modeling needs |
Not relevant; not requested at this time. |
| Digital elevation data needs |
Lidar variable over large focus area; some areas complete, others in progress. |
