World Library  
Flag as Inappropriate
Email this Article

Canyon

Article Id: WHEBN0000078478
Reproduction Date:

Title: Canyon  
Author: World Heritage Encyclopedia
Language: English
Subject: Wadi, List of landforms, Paklenica, List of Warcraft locations, Grand Canyon of the Yellowstone
Collection: Canyons and Gorges, Erosion Landforms, Fluvial Landforms
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Canyon

Grand Canyon, Arizona, at the confluence of the Colorado and Little Colorado rivers
Boğazpınar Canyon, Mersin Province, Turkey
Itaimbezinho Canyon, at Aparados da Serra National Park, Brazil
One of three gorges on Yangtze river, China
Sianok canyon in Bukittinggi, Indonesia
Nepal

A gorge or canyon (cañon, old spelling occasionally still used) is a deep ravine between pairs of escarpments or cliffs and is the most often carved landscape by the erosive activity of a river over geologic timescales. Rivers have a natural tendency to cut through underlying surfaces so will eventually wear away rock layers to lessen their own pitch slowing their waters; given enough time, their bottoms will gradually reach a baseline elevation—which is the same elevation as the body of water it will eventually drain into. This action, when the river source and mouth are at much different base elevations will form a canyon,[1] particularly through regions where softer rock layers are intermingled with harder layers more resistant to weathering.

A canyon may also refer to a rift between two mountain peaks, such as those in ranges including the box canyons. Slot canyons are very narrow canyons, often with smooth walls.

Contents

  • Etymology 1
  • Formation 2
    • Box canyon 2.1
  • Largest canyons 3
  • Cultural significance 4
  • Lists 5
    • List of notable canyons and gorges 5.1
    • List of other features causing gorges or canyons 5.2
  • Canyons on other planetary bodies 6
  • See also 7
  • References 8
  • External links 9

Etymology

The word canyon is Spanish in origin (cañón,[2] pronounced: , meaning big caña, defile is occasionally used in the United Kingdom.

Formation

Most canyons were formed by a process of long-time erosion from a plateau or table-land 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 than in wet areas because physical weathering has a more localized effect in arid zones. The wind and water from the river combine to erode and cut away less resistant materials such as shales. 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, in a process known as frost wedging.[3] Canyon walls are often formed of resistant sandstones or granite. Submarine canyons form underwater, generally at the mouths of rivers.

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

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

Box canyon

A box canyon is a small ravine or canyon with steep walls on three sides, allowing access and egress only through the mouth of the canyon. Box canyons were frequently used in the American West as convenient corrals, with their entrances fenced.[4] They were also used as kill sites for wild game, which could be driven into the confined space and killed.[5]

Largest canyons

The definition of "largest canyon" is 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 deepest canyon in the world, the Indus Gorge with Nanga Parbat, the world's 9th highest mountain rising to the south.

The deepest canyon in the world is at the confluence of the Kashmir.

The Kali Gandaki Gorge in midwest Nepal as the deepest canyon, with a 6400 m (21,000 ft) difference between the level of the river and the peaks surrounding it.

View of Grand Canyon from Space Shuttle Challenger.

Vying for deepest canyon in the Americas are the Cotahuasi Canyon and Colca Canyon, in southern Peru. Both have been measured at over 3500 m (12,000 ft) deep.

The Grand Canyon of northern Arizona in the United States, with an average depth of 1,600 m (one mile) and a volume of 4.17 trillion cubic metres,[7] is one of the world's largest canyons. It was among the 28 finalists of the New7Wonders of Nature worldwide poll. (Some referred to it as one of the 7 natural wonders of the world.[8]) Copper Canyon in Chihuahua, Mexico is deeper and longer than the Grand Canyon.

The largest canyon in Africa is the Fish River Canyon in Namibia.[9]

In August 2013, the discovery of Greenland's Grand Canyon was reported. Located under an ice sheet, based on the analysis of date from Operation IceBridge, it is believed to be the longest canyon in the world.[10]

Cultural significance

Some canyons have notable cultural significance. Evidence of early humanoids has been discovered in Africa's archeologically because of the many cliff-dwellings built in such areas, largely by the ancient Pueblo people who were their first inhabitants.

Lists

List of notable canyons and gorges

Washington and northern Oregon, United States
Bicaz Canyon, Romania
Fjaðrárgljúfur Canyon, Iceland
Murchison River Gorge, Australia
Katherine Gorge, Australia
Pakistan
Georgia
Launceston, Tasmania, Australia

Americas

Africa

Europe

Asia

Australia

  • Victoria
  • Queensland
  • Bouldercombe Gorge, Queensland
  • Cambanoora Gorge, Queensland
  • Carnarvon Gorge, Queensland
  • Tasmania
  • Western Australia
  • New South Wales
  • Northern Territory
  • Kings Canyon, Northern Territory
  • Lerderderg Gorge, Victoria
  • Loch Ard Gorge, Victoria
  • Little River Gorge, Victoria
  • Mossman Gorge, Queensland
  • Murchison River Gorge, Western Australia
  • Nepean Gorge, New South Wales
  • North and South Gorges of North Stradbroke Island, Queensland
  • Porcupine Gorge, Queensland
  • Palm Valley, Northern Territory
  • Ravine des Casoars, South Australia
  • Sturt Gorge, South Australia
  • Windjana Gorge, Western Australia

New Zealand

List of other features causing gorges or canyons

Canyons on other planetary bodies

Venus has many craters and canyons on its surface. The troughs on the planet are part of a system of canyons that is more than 6 400 km long.

See also

References

  1. ^ http://www.mountainnature.com/Geology/Canyons.htm
  2. ^  
  3. ^ "The Geology of the Grand Canyon". Retrieved 2015-10-01. 
  4. ^ "box canyon". Encarta World English Dictionary. 2009. Archived from the original on 2009-10-31. Retrieved 2009-08-04. 
  5. ^ "Wardell Buffalo Trap". Wyoming State Historic Preservation Office. Retrieved 2009-08-04. 
  6. ^ http://www.kepu.net.cn/english/canyon/hiking/hik301.html
  7. ^ National Park Service
  8. ^ Truong, Alice (1 July 2011). "Everything About the Grand Canyon". Discovery Communications. Retrieved 5 February 2012. 
  9. ^ Cohen, Callan, Claire Spottiswoode and Jonathan Rossouw (2006) Southern African Birdfinder ISBN 1-86872-725-4, page 210
  10. ^ "Grand Canyon of Greenland Discovered under Ice", Discovery

External links

Media related to at Wikimedia Commons

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.