Canyon
Wiki, Facts

 Canyon facts

• 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, 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 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 have an opening on only one side are called box canyons
• Slot canyons are very narrow canyons, often with smooth walls
• Steep-sided valleys in the seabed of the continental slope underwater are referred to as submarine canyons
• Unlike canyons on land, submarine canyons are thought to be formed by turbidity currents and underwater landslides