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The Grand Canyon, Arizona, at the confluence of the Colorado River and Little Colorado River.. A canyon (from Spanish: cañón; archaic British English spelling: cañon), [1] gorge or chasm, is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic time scales. [2]
The resulting Grand Canyon Supergroup of sedimentary units is composed of nine varied geologic formations that were laid down from 1.2 billion and 740 million years ago in this sea. [11] Good exposures of the supergroup can be seen in eastern Grand Canyon in the Inner Gorge and from Desert View, Lipan Point and Moran point. [12] [note 1]
The oldest beds of this formation belong to the Dinosaur Canyon Member, a reddish, slope-forming rock layer with thin beds of siltstone that are interbedded with mudstone and fine sandstone. [11] The Dinosaur Canyon, with a local thickness of 140 to 375 feet (43 to 114 m), was probably laid down in slow-moving streams, ponds and large lakes. [7]
The canyon itself can act as a connection between the east and the west by providing corridors of appropriate habitat along its length. [145] The canyon can also be a genetic barrier to some species, like the tassel-eared squirrel. [145] The aspect, or direction a slope faces, also plays a major role in adding diversity to the Grand Canyon.
The Mesoproterozoic formations in the Grand Canyon are overlain by the 850 million year old, Neoproterozoic Chuar Group and Sixtymile Formation sedimentary rocks. The Great Unconformity is a famous gap in the stratigraphic record of the Grand Canyon of 900 million years between Proterozoic granitic rocks and Cambrian marine sediments. For the ...
Navajo Upper Antelope Canyon is a slot canyon in the American Southwest, on Navajo land east of Lechee, Arizona.It includes six separate, scenic slot canyon sections on the Navajo Reservation, referred to as Upper Antelope Canyon (or The Crack), Rattle Snake Canyon, Owl Canyon, Mountain Sheep Canyon, Canyon X [4] and Lower Antelope Canyon (or The Corkscrew). [2]
A submarine canyon is a steep-sided valley cut into the seabed of the continental slope, sometimes extending well onto the continental shelf, having nearly vertical walls, and occasionally having canyon wall heights of up to 5 km (3 mi), from canyon floor to canyon rim, as with the Great Bahama Canyon. [1]
Unstable geology is prevalent throughout the canyon, and occasional rockslides have formed impounded lakes in the canyon, the most recent of which was roughly 4,000 years ago. Owing to the extreme depth of the canyon, there are many springs fed by the surrounding groundwater, permitting water in the canyon to run year-round. [5] [6]