Capitol Reef National Park

Geology
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Wall close-up, Capitol Reef National Park
Wall close-up, Capitol Reef National Park (Nathan Borchelt)

Crytogamic/Cryptobiotic Soil

Cryptogamic soil is actually alive, composed of several species of mosses, lichens, fungi and algae. It protects the soil from erosion, absorbs moisture, and provides nitrogen and other nutrients for plant growth. Step on this very valuable plant community, however, and it may die. At best it will take years to restore, longer to eradicate the scar of your footprint. Cryptogamic soil crust is often referred to as "brown sugar soil." This dark, cruddy looking soil covers much of the terrain of untrampled desert areas.

Cryptogamic soil gets its name from the Greek words kryptos (hidden) and gamia (marriage), relating to the lack of any flowers for reproduction in these "lower" plants. They reproduce by spores. Cryptogamic soil fits into one of nature's neat little plans, the composition of the crust varies by locality, yet, basically, all cryptogamic soil serves the same purpose. The cryptogams form a spongy surface covering that absorbs moisture. In freezing temperatures, the spongy mass uplifts and cracks. The cracks, in turn, hold more moisture. The spongy mass and the cracks provide traps for seeds and stabilize the soil so it will stay in place long enough for seeds to sprout and grow. Plant communities develop. A vegetated area results, which, were it not for the cryptogamic soil crust, might very well be barren.

You may wonder why you should avoid trampling cryptogamic soil when, indeed, disturbance by frost and uplift aids its purpose. The answer is a fine line between disturbed and destroyed crust—continued trampling would destroy the fragile blanket, while the buckling action of frost merely loosens the surface.

As you hike the canyon country, the soil is easy to spot. It nearly blankets the Colorado Plateau. Without it, you might be looking at quite a different terrain—still rugged and colorful, but void of much of the green flora that brings it alive.

Waterpocket Fold

The Waterpocket Fold is the geologic centerpiece of Capitol Reef National Park. Most of the 100-mile length of the Waterpocket Fold is included within park boundaries that extend from Thousand Lake Mountain to the Colorado River. The ridge of resistant sandstone tilted up by the Fold gives, at least in part, Capitol Reef its name. The ridge was a barrier to travel and such barriers were called "reefs."

The tilt of the rock layers along Capitol Reef reveals the structure of the Fold. The Waterpocket Fold is a type of fold with one steep side called a monocline. In this case, the steep limb of the monocline is the east side where the rock layers are tilted as much at 60 degrees from their original horizontal position. A monocline is a "step up" and the fold here has lifted the rocky layers on the west side 7,000 feet higher relative to the layers on the east.

Nearly 10,000 feet of sedimentary rocks are exposed in and around Capitol Reef. The rock layers exposed in the park range in age from approximately 270 to 65 million years old. The most spectacular of the formations exposed in the Capitol Reef area are the sandstones of the Glen Canyon Group: The Wingate Sandstone and the Kayenta Formation combine to form the dramatic red cliffs near Fruita and along the Scenic Drive. The eroded "petrified dunes" of the Navajo Sandstone above the Fruita cliffs reminded early settlers of the rotundas of capitol buildings in Washington, D.C. Not only does the Navajo Sandstone create these white slickrock domes, it is also responsible for most of the narrows, slot canyons, and waterpockets found in Capitol Reef.

The dramatic scenery of Capitol Reef is the result of the erosion of the various rock layers during more recent geologic times. River erosion, flash floods, rock falls, and other erosional events have shaped the landscape into cliffs and slopes, natural arches and bridges, spires and monoliths, and even castles.

The landscape of Capitol Reef intimately reveals the park's geology. To fully appreciate the scenery, both the rock layers and erosional forces that shaped Capitol Reef must be appreciated. For more information about Capitol Reef's stratigraphy, including thickness, rock types, and depositional environments, please see the National Parks Service electronic visitor center.


Published: 29 Apr 2002 | Last Updated: 6 Jan 2011
Details mentioned in this article were accurate at the time of publication

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