Editing Sedimentary rock (section)

==Sedimentation rates==
The rate at which sediment is deposited differs depending on the location. A channel in a tidal flat can see the deposition of a few metres of sediment in one day, while on the deep ocean floor each year only a few millimetres of sediment accumulate. A distinction can be made between normal sedimentation and sedimentation caused by catastrophic processes. The latter category includes all kinds of sudden exceptional processes like [[Mass wasting|mass movements]], [[rock slide]]s or [[flood]]ing. Catastrophic processes can see the sudden deposition of a large amount of sediment at once. In some sedimentary environments, most of the total column of sedimentary rock was formed by catastrophic processes, even though the environment is usually a quiet place. Other sedimentary environments are dominated by normal, ongoing sedimentation.{{sfn|Reading|1996|p=17}}

In many cases, sedimentation occurs slowly. In a [[desert]], for example, the wind deposits siliciclastic material (sand or silt) in some spots, or catastrophic flooding of a [[wadi]] may cause sudden deposits of large quantities of detrital material, but in most places eolian erosion dominates. The amount of sedimentary rock that forms is not only dependent on the amount of supplied material, but also on how well the material consolidates. Erosion removes most deposited sediment shortly after deposition.{{sfn|Reading|1996|p=17}}

[[File:SEUtahStrat.JPG|thumb|upright=1.4|The [[Permian]] through [[Jurassic]] stratigraphy of the [[Colorado Plateau]] area of southeastern [[Utah]] that makes up much of the famous prominent rock formations in protected areas such as [[Capitol Reef National Park]] and [[Canyonlands National Park]]. From top to bottom: Rounded tan domes of the [[Navajo Sandstone]], layered red [[Kayenta Formation]], cliff-forming, vertically jointed, red [[Wingate Sandstone]], slope-forming, purplish [[Chinle Formation]], layered, lighter-red [[Moenkopi Formation]], and white, layered [[Cutler Formation]] sandstone. Picture from [[Glen Canyon National Recreation Area]], Utah.]]