| State | Colorado |
|---|---|
| Name | Mafic rocks of 1700-m.y. age group |
| Geologic age | Early Proterozoic |
| Lithologic constituents |
Major
Igneous > Plutonic > Gabbroic > Gabbro
Igneous > Plutonic > Dioritic > Diorite
Minor
Igneous > Plutonic > Syenitic > Monzonite
|
| References | Tweto, Ogden, 1979, Geologic Map of Colorado: U.S. Geological Survey Special Geologic Map, scale 1:500,000. |
| NGMDB product | |
| Counties | Alamosa - Chaffee - Costilla - Custer - Fremont - Gilpin - Grand - Gunnison - Huerfano - Jackson - Routt - Saguache |