A canyon is a deep cleft between escarpments or cliffs formed by geological processes over long periods of time. These landforms result from the combined effects of weathering and the erosive activity of a river as it cuts through underlying surfaces.
The formation occurs because rivers naturally wear away rock layers as sediments are transported downstream toward a baseline elevation. Canyons specifically develop when a river's headwaters and estuary are at significantly different elevations, particularly in regions where softer rock layers are intermingled with harder, more resistant layers.