Canyon

A canyon is a deep, narrow valley with steep sides, usually shaped over a long period by the erosion of flowing water. Rivers carry sediment that gradually wears away rock, while weathering and occasional landslides help weaken and widen the valley walls. Erosion depends on rock type, climate, river flow, and transported sediment.

When land rises, a river can cut downward faster and form a deep gorge. Not every canyon is carved only by a river: some are influenced by glaciers, tectonic activity, or a combination of processes. Canyons can therefore vary greatly in shape, depth, and rock layers.

One of the best-known examples is the Grand Canyon in the southwestern United States, where the Colorado River has cut through layers of rock over millions of years. Its walls expose rocks of different ages, allowing geologists to study the region's geological history. Canyons also occur in deserts, mountains, plateaus, and other landscapes around the world.

They may contain rivers, streams, vegetation, and habitats that differ from those on the surrounding land. Because their steep walls and narrow floors can limit access and sunlight, conditions inside a canyon may change over short distances. A canyon is therefore not simply a large crack in the ground, but a landform produced by interacting geological and surface processes over long periods of time.