|
An escarpment is a steep slope or long cliff that occurs from faulting, tilting or warping and resulting erosion and separates two relatively level areas of differing elevations. Usually ''escarpment'' is used interchangeably with scarp (from the Italian ''scarpa'', shoe〔(''scarp'' - Definition from the Merriam-Webster Online Dictionary )〕). But some sources differentiate the two terms, where ''escarpment'' refers to the margin between two landforms, while ''scarp'' is synonymous with a cliff or steep slope.〔Easterbrook, D. J. (1999) Surface processes and landforms. (Second Ed). Prentice Hall, Upper Saddle River, New Jersey.〕〔(Summary: Escarpments ), US Army Corps of Engineers.〕 The surface of the steep slope is called a scarp face. ==Formation and description== Scarps are generally formed by one of two processes: either by differential erosion of sedimentary rocks, or by 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 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. More loosely, the term scarp describes the zone between coastal lowlands and continental plateaus which have a marked, abrupt change in elevation caused by coastal erosion at the base of the plateau. 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. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Escarpment」の詳細全文を読む スポンサード リンク
|