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An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations.
The terms scarp and scarp face are often used interchangeably with escarpment.[citation needed] Some sources differentiate the two terms, with escarpment referring to the margin between two landforms, and scarp referring to a cliff or a steep slope.[1][2] In this usage an escarpment is a ridge which has a gentle slope on one side and a steep scarp on the other side.
More loosely, the term scarp also describes a zone between a coastal lowland and a continental plateau which shows a marked, abrupt change in elevation[3] caused by coastal erosion at the base of the plateau.
Formation and description
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Scarps are generally formed by one of two processes: either by differential erosion of sedimentary rocks, or by movement of the Earth's crust at a geologic fault. The first process is the more common type: the escarpment is a transition from one series of sedimentary rocks to another series of a different age and composition. Escarpments are also frequently formed by faults. When a fault displaces the ground surface so that one side is higher than the other, a fault scarp is created. This can occur in dip-slip faults, or when a strike-slip fault brings a piece of high ground adjacent to an area of lower ground.
Earth is not the only planet where escarpments occur. They are believed to occur on other planets when the crust contracts, as a result of cooling. On other Solar System bodies such as Mercury, Mars, and the Moon, the Latin term rupes is used for an escarpment.
Erosion
editWhen sedimentary beds are tilted and exposed to the surface, erosion and weathering may occur. Escarpments erode gradually and over geological time. The mélange tendencies of escarpments results in varying contacts between a multitude of rock types. These different rock types weather at different speeds, according to Goldich dissolution series so different stages of deformation can often be seen in the layers where the escarpments have been exposed to the elements.
See also
edit- Cuesta – Hill or ridge with a gentle slope on one side and a steep slope on the other
- Fall line – Meeting point of uplands and coastal plain
- List of escarpments
References
edit- ^ Easterbrook, Don J. (1999). Surface Processes and Landforms. Prentice Hall. ISBN 978-0-13-860958-0.[page needed]
- ^ Summary: Escarpments, US Army Corps of Engineers.
- ^ "Scarps and Terraces". Physiography. Radford University. Retrieved 24 December 2020.