canyon

Grand Canyon, Arizona

Noravank Monastery complex and canyon in Armenia.

Aerial view of canyons in western United States.

A canyon, occasionally spelt 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 greater 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 military derived word defile is occasionally used in England.

A famous example is the Grand Canyon in Arizona with an average depth of one mile and a volume of 4.17 trillion cubic meters.^[1] In the southwestern United States, canyon 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.

A canyon may also refer to a rift between two mountain peaks such as those in ranges such as the Rocky Mountains, the Alps, the Himalayas or the Andes. Usually a river or stream and erosion carve out such splits between mountains. Examples of mountain type canyons are Provo Canyon in Utah or Yosemite National Park in California's Sierra Nevada. Canyons within mountains or gorges that only have an opening on one side are called box canyons. Slot canyons are very narrow canyons, often with smooth walls.

Largest canyons

• Grand Canyon in Arizona, USA
• Copper Canyon in Chihuahua, Mexico

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 Zangbo Grand Canyon, along the Yarlung Tsangpo River in Tibet, China, is regarded by some as the deepest canyon in the world, and is slightly longer than Grand Canyon making it one of the world's largest.

Lists

List of canyons

Gorges of Ak-Shur.

• Black Canyon of the Gunnison, Colorado, USA
• Blyde River Canyon, Mpumalanga, South Africa
• Charyn Canyon, Kazakhstan
• Chicamocha Canyon, Santander, Colombia
• Saturban canyon, Santander, Colombia
• Colca Canyon, Arequipa, Peru
• Cotahuasi Canyon, Arequipa, Peru
• Dirk River Canyon, Montenegro, Europe
• Fish River Canyon, Namibia, Africa
• Fraser Canyon, British Columbia, Canada
• Grand Canyon of the Yellowstone, Wyoming, USA
• Guartelá Canyon, Paraná, Brazil
• Hells Canyon, Idaho and Oregon, USA
• Horseshoe Canyon, Alberta, Canada
• Huasteca Canyon, Monterrey, Mexico
• Kings Canyon (Northern Territory), Australia
• Nfeye Canyon, Portugal
• Nine Mile Canyon, Utah, USA
• Ouimet Canyon, Ontario, Canada
• Palo Duro Canyon, Texas, USA
• Rugova Canyon, Kosovo, Europe
• Shnizow Canyon, Uşak, Turkey
• Sumidero Canyon, Chiapas, Mexico
• Valla Canyon, Kure,Turkey
• Waimea Canyon, Hawaii, USA
• Yarlung Zangbo Grand Canyon, Tibet Autonomous Region, China

List of gorges

Swaan gorge

• Avon Gorge, Bristol, England
• Bog Walk Gorge, Saint Catherine Parish, Jamaica
• Bued Gorge, Benguet, Philippines
• Cataract Gorge, Launceston, Australia
• Cheddar Gorge, Somerset, England
• Columbia River Gorge, USA
• Corrieshalloch Gorge, Ullapool, Scotland
• Galston Gorge, NSW, Australia
• Ironbridge Gorge, Shropshire, England
• Kloof, KwaZulu-Natal, South Africa (The word Kloof means 'gorge' in Afrikaans)
• Komati Gorge, South Africa
• Lanner Gorge, South Africa
• Manawatu Gorge, Manawatu, North Island, New Zealand
• Montalban Gorge, Philippines
• New River Gorge, West Virginia, USA
• Katherine Gorge of Nitmiluk National Park in Australia
• Pankisi Gorge, Georgia (country)
• Pine Creek Gorge, Pennsylvania, USA
• Red River Gorge, Kentucky, USA
• Royal Gorge, Colorado, USA
• Samaria Gorge, Crete, Greece
• Talari Gorges, Mali
• Gorges du Tarn, France
• Taroko Gorge of Taroko National Park, Taiwan
• Three Gorges, Hubei, China
• Tiger Leaping Gorge, Yunnan, China
• Verdon Gorge, Provence, France
• Vikos Gorge, Vikos-Aoos National Park, Greece

List of other features causing gorges or canyons

• Ardèche River, France
• Bued River, Philippines
• Danube River, Europe, including the Iron Gate
• Kings River of the Kings Canyon National Park, California, USA
• South Nahanni River in Canada[1]
• Steall Waterfall of Glen Nevis, Lochaber, Scotland
• Swaan River in the Pothohar Plateau, Pakistan

Canyons on other planetary bodies

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

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

• Canyoning
• Geomorphology
• Gully
• List of landforms
• Ravine

Notes