Scarp (landform)

small step or offset on the ground surface where one side of a fault has moved vertically with respect to the other
(Redirected from Escarpment)
A fault scarp created by the 1983 Borah Peak earthquake
Escarpment face broken by a fault, Cumberland Plateau, Tennessee

Scarp is a term in geology and geography with several similar meanings.

  • A scarp is a cliff or steep slope.[1][2] The word is derived from the Italian scarpa, meaning 'shoe'.[3]
    • The surface of the steep slope is called a scarp face.
  • A fault scarp is a steep cliff made by movement along one side of a fault.
  • An escarpment is a steep slope or long cliff that occurs from faulting and resulting erosion. It separates two relatively level areas of different height.
    • A cuesta is an asymmetric ridge with an escarpment on one side and a gentle dip slope on the other side.

FormationEdit

Scarps are generally formed by one or both:

  1. differential erosion of sedimentary rocks, or by
  2. vertical movement of the Earth's crust along a geologic fault.

Most commonly, an 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 brings a piece of high ground next to an area of lower ground.

More loosely, the term scarp describes the zone between coastal lowlands and continental plateaus. A marked, abrupt change in height is caused by coastal erosion at the base of the plateau.

 
Schematic cross section of a cuesta, dip slopes facing left, and harder rocklayers in darker colors than softer ones.

ReferencesEdit

  1. Easterbrook, D. J. 1999. Surface processes and landforms. 2nd ed, Prentice Hall, New Jersey.
  2. Summary: Escarpments, US Army Corps of Engineers.
  3. scarp - Definition from the Merriam-Webster Online Dictionary