Mafic rocks of 1700-m.y. age group

Gabbro and mafic diorite and monzonite
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