Assign_3_3 - The Grand Canyon in Colorado was carved by the...

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A canyon is a deep  ravine  between  cliffs  often carved from the landscape by a river. Most  canyons were formed by a process of long-time  erosion  from a  plateau  level. The  cliffs  form  because harder rock strata that are  resistant  to erosion and weathering remain exposed on the  valley walls. Canyons are more common in arid areas than in wet areas because physical  weathering has a greater effect in dry areas. The wind and water from the river combine to erode  and cut away less resistant materials such as shale. The freezing and expansion of water also  serves to help form canyons. Water seeps into cracks between the rocks and freezes, pushing the  rocks apart and eventually causing large chunks to break off the canyon walls. Canyon walls are  often formed of  sandstones  and  granite
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Unformatted text preview: . The Grand Canyon in Colorado was carved by the Colorado River. It is about 300 miles long and up to 20 miles wide in certain parts. The Grand Canyon attains a depth of over 1 mile. The greatest geologic importance of the Grand Canyon lies in the millions of years of history its walls display. As the Colorado River cut through the prehistoric rock, it revealed a cross section that tells us a great deal about the history of the Grand Canyon and what type of materials the Grand Canyon is made of. Geologists have found many fossil samples that help date the formation of the Grand Canyon back to some 17 million years ago. Textbook: Page 547 Physical Geography: A Landscape Appreciation, by Tom McKnight and Darrel Hess, 9 th Edition....
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This note was uploaded on 10/22/2011 for the course PSYC 311 taught by Professor Mayhew during the Fall '11 term at Rutgers.

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