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Clem Powell reading while sitting on a boulder in Cataract Canyon, Colorado
River. Arizona.
USGS Earth Science Photographic Archive digital file: hjk00603
Downstream of the Confluence with the Green River, the gradient of the
Colorado increases, and the result is what Powell aptly named, Cataract
Canyon. Cataract Canyon extends downstream for almost 50 miles with a
drop of over 400 feet. Cataract Canyon extends to Mille Crag Bend, about
5 miles upstream of the mouth of the Dirty Devil River (which is located
near Hite Crossing on Lake Powell). Cataract Canyon follows a system of
fractures that trend toward the southwest. As the river has carved downward
the landscape along the river has raised, forming a series of anticlinal
folds along the path of the river. The arching along the river path is
probably the result of salt flowing gradually upward under the canyon
due to the release of overburden pressure as the river carves downward.
The salt beds are hundreds to thousands of feet below the surface in the
lower Paradox Formation (Pennsylvanian age). Only sandstone and shale
of the uppermost beds of the Paradox Formation are exposed in parts of
Cataract Canyon.
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