A ‘grand’ canyon: Glenwood Canyon
Glenwood Canyon is geologically every bit as fascinating as its more famous North American neighbor, the Grand Canyon. Photo: Jeremy Joseph, graduate of the Colorado Mountain College Professional Photography Program.
How was the canyon formed? The ancestral Colorado River flowed 2400 feet above its current location more than three million years ago. Inch by inch, it carved through and exposed sedimentary layers not visible from the panorama of Glenwood Springs itself.
This erosion exposed 1700 million years of formations as old as the Precambrian era rocks you see at various points along the highway and bike path in the Canyon.
By some estimates, this rate of erosion occurred at about 10 inches per every thousand years.
This canyon has it all. Glenwood Canyon contains all three types of rocks: sedimentary, igneous and metamorphic. As you travel through the canyon, be sure to stop at one of its many rest areas and use these photos as your guide to identifying the formations:
Geologic Time Scale of Glenwood Canyon:
|FORMATION||THICKNESS (in meters)||PERIOD||ERA|
(318-299 million years ago)
|Pre-cambrian (Proterozoic) Igneous and Metamorphic Rocks
(1,700 million years old)
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