Title | Black Canyon at Black Canyon of the Gunnison National Park |
Description | In Black Canyon of the Gunnison National Park, the Gunnison River has eroded a deep canyon in 2-billion year old Precambrian rock. The overlooks along the South Rim Drive in the National Park offer excellent views of the canyon and of its ancient rocks. Metamorphic rock dominates the canyon walls; both gneiss and (lesser amounts of) schist are present. These rocks formed deep below the Earth's surface and so are highly deformed. They are cut by many pegmatite dikes and blobs. The pegmatite has granitic composition, and in many places appears pink because the granite contains large pink K-feldspar crystals. |
Chronostratigraphy | Precambrian |
Lithostratigraphy | Black Canyon Gneiss |
Location | USA ▹ Colorado ▹ Gunnison. Near Gunnison. Black Canyon of the Gunnison National Park. |
Photographer | Dexter Perkins. 1999. |
Collection | E181030992F-16. |
Key words | Black Canyon of the Gunnison, granite, Colorado, dike |
Tech details | 532 KB. Vista. Canon EOS Rebel, 55mm, Kodak Elite Chrome 100 ASA. |
GeoDIL number | 1728 |
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