Find us on facebook!
About CGS
Avalanche Info Center
Colorado Geology
Energy Resources
Geologic Hazards
Geologic Mapping
Geological Research
Land Use Regulations
Mineral Resources
Click on images to enlarge
Exfoliation dome in 1.4-billion-
year-old granitic batholith of
Rocky Mountain National Park
The Diamond face of Longs
Peak - Highest point of the
Estes Park batholith
Rocks of Colorado's youngest
batholith form Cathedral Park
along Gold Camp Road
Granitic dome - Estes Park
batholith in Rocky Mountain
National Park
A batholith is a very large (outcrop area greater than 40 square miles and no known floor) intrusive mass of solidified magma, usually granitic in composition. These are emplaced deep in the crust and are irregular in shape.

Proterozoic granitic batholiths are common throughout Colorado's Rocky Mountains.  It was generally thought that the batholiths fell into three age groups: the Routt plutonic suite at about 1.7 billion years ago, the Berthoud plutonic suite at about 1.4 billion, and the Pikes Peak batholith at about 1.0 billion.  With more age dating, and more advanced dating techniques, we are discovering that the intrusions were more spread out in time.

Decades ago geologists thought that foliated granitic intrusions belonged to the Routt suite and non-foliated granitic plutons belonged to the Berthoud suite.  However, the modern dating is showing this not to be the case.

Below: Granitic batholiths of Colorado, from Tweto, 1979.

Last Updated: 1/24/2013 11:50 AM 
News  |  About Us  |  Site Map  |  Staff Directory  |  Licensing  |