| State | Colorado |
|---|---|
| Name | Volcanic rocks in northwestern Colorado |
| Geologic age | Tertiary |
| Lithologic constituents | Major
Igneous > Volcanic > Mafic-volcanicintermediate composition
|
| References | Tweto, Ogden, 1979, Geologic Map of Colorado: U.S. Geological Survey Special Geologic Map, scale 1:500,000. |
| NGMDB product | |
| Counties | Grand - Jackson - Larimer - Moffat - Routt - Summit |