Difference between revisions of "Canyon" - New World Encyclopedia

From New World Encyclopedia
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*[[Valles Marineris]] on [[Mars]] is the largest known canyon in the solar system
 
*[[Valles Marineris]] on [[Mars]] is the largest known canyon in the solar system
 
*[[Ithaca Chasma]] on [[Saturn]]'s moon [[Tethys (moon)|Tethys]]
 
*[[Ithaca Chasma]] on [[Saturn]]'s moon [[Tethys (moon)|Tethys]]
 
 
  
 
==See also==
 
==See also==
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== References ==
 
== References ==
 +
 +
* Abbott, Lon, and Terri Cook. 2004. ''Hiking the Grand Canyon's Geology.'' Seattle, WA: Mountaineers Books. ISBN 0898868955.
 +
 +
* Beus, Stanley S., and Michael Morales. 2003. ''Grand Canyon Geology.'' 2nd ed. New York: Oxford University Press. ISBN 0195122992.
 +
 +
* Erickson, Jon. 2001. ''Rock Formations and Unusual Geologic Structures.'' Exploring the Earth's Surface. New York: Facts on File. ISBN 0816043280.
 +
 +
* Plummer, Charles C., David McGeary, and Diane H. Carlson. 2005. ''Physical Geology.'' Boston: McGraw-Hill. ISBN 007252815X.
 +
 +
* Whitney, Stephen. 1996. ''A Field Guide to the Grand Canyon.'' Seattle, WA: Mountaineers. ISBN 0898864895.
  
 
==External links==
 
==External links==
 
All links retrieved September 29, 2007.
 
All links retrieved September 29, 2007.
* [http://www.canyonsworldwide.com/index.html CANYONS WORLDWIDE .com], Grand Canyons of the Earth.
+
* [http://www.canyonsworldwide.com/index.html Grand Canyons of Earth.] ''canyonsworldwide.com''.
 
* [http://www.friendsoftheravines.org Friends of the Ravines]
 
* [http://www.friendsoftheravines.org Friends of the Ravines]
 
* [http://balashon.blogspot.com/2006/06/canyon.html Etymology of "canyon"]
 
* [http://balashon.blogspot.com/2006/06/canyon.html Etymology of "canyon"]

Revision as of 18:51, 12 October 2007

Noravank Monastery complex and canyon in Armenia.

A canyon (rarely cañon) or gorge is a deep valley 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 much more common in arid areas than in wetter areas because weathering has a lesser effect in arid zones. Canyon walls are often formed of resistant sandstones or granite. Submarine canyons are those which form underwater, generally at the mouths of rivers. The word canyon is Spanish in origin (cañón). The word canyon is generally used in the United States, while the word gorge is more common in Europe and Oceania, though it is also used in some parts of the United States and Canada. The rare word defile is occasionally used in England.

A famous example is the Grand Canyon in Arizona. In the southwestern United States, canyons are important archeologically because of the many cliff-dwellings built there, largely by the earlier inhabitants, Ancient Pueblo Peoples.

Sometimes large rivers run through canyons as the result of gradual geologic uplift. These are called entrenched rivers, because they are unable to easily alter their course. The Colorado River and the Snake River in the northwestern United States are two examples of tectonic uplift.

Canyons often form in areas of limestone rock. Limestone is to a certain extent soluble, so cave systems form in the rock. When these collapse a canyon is left, for example in the Mendip Hills in Somerset and Yorkshire Dales in Yorkshire, England.

Largest canyons

The definition of "largest canyon" is rather imprecise, as a canyon can be "large" by its depth, length, or the total area of the canyon system. Also the inaccessibility of the major canyons in the Himalaya contributes to their not being regarded as candidates for the biggest canyon. The definition of "deepest canyon" is similarly imprecise, especially if one includes mountain canyons as well as canyons cut through relatively flat plateaus (which have a somewhat well-defined rim elevation).

The Yarlung Tsangpo Canyon, along the Yarlung Tsangpo River in Tibet, China, is regarded by some as the deepest canyon in the world, and is even slightly longer than Grand Canyon. Hence it is regarded by many as the world's largest canyon, followed by the Kali Gandaki Gorge[1] in Nepal, Polung Tsangpo Canyon in Tibet, Cotahuasi Canyon (3,535 m deep and the deepest in the Americas), and the Tekezé gorge (2000m+ deep and deepest in Africa).[2]

Slot canyons are very narrow canyons, often with smooth walls.

Other well-known canyons

Other lesser-known canyon systems include:

  • Black Dragon Canyon in Utah, USA
  • Swaan River makes many gorges in Pothohar plateau Pakistan.

The Blue Mountains west of Sydney in New South Wales, Australia contain many gorges carved into the sandstone rock.

Canyons on other planetary bodies

  • Valles Marineris on Mars is the largest known canyon in the solar system
  • Ithaca Chasma on Saturn's moon Tethys

See also

Notes

  1. If one measures the depth of a canyon by the difference between the river height and the heights of the highest peaks on either side, the Kali Gandaki Gorge is the world's deepest. The portion of the river between the Dhaulagiri and Annapurna massifs is at an elevation of between 1300 meters and 2600 meters, 5500 to 6800 meters lower than the two peaks. See Annapurna (1:100,000 map), Nepal-Kartenwerk der Arbeitgemeinschaft für vergleichende Hochgebirgsforschung Nr. 9, Nelles Verlag, Munich, 1993. Also see Google Earth.
  2. Noia 64 mimetypes pdf.pngPDF

References
ISBN links support NWE through referral fees

  • Abbott, Lon, and Terri Cook. 2004. Hiking the Grand Canyon's Geology. Seattle, WA: Mountaineers Books. ISBN 0898868955.
  • Beus, Stanley S., and Michael Morales. 2003. Grand Canyon Geology. 2nd ed. New York: Oxford University Press. ISBN 0195122992.
  • Erickson, Jon. 2001. Rock Formations and Unusual Geologic Structures. Exploring the Earth's Surface. New York: Facts on File. ISBN 0816043280.
  • Plummer, Charles C., David McGeary, and Diane H. Carlson. 2005. Physical Geology. Boston: McGraw-Hill. ISBN 007252815X.
  • Whitney, Stephen. 1996. A Field Guide to the Grand Canyon. Seattle, WA: Mountaineers. ISBN 0898864895.

External links

All links retrieved September 29, 2007.

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