This article will be permanently flagged as inappropriate and made unaccessible to everyone. Are you certain this article is inappropriate? Excessive Violence Sexual Content Political / Social
Email Address:
Article Id: WHEBN0000495980 Reproduction Date:
In geology, a graben is a depressed block of land bordered by parallel faults. Graben is German for ditch or trench. The plural form is variously given as graben[1] or grabens.[2]
A graben is the result of a block of land being downthrown producing a valley with a distinct scarp on each side. Graben often occur side-by-side with horsts. Horst and graben structures are indicative of tensional forces and crustal stretching.
Graben are produced from parallel normal faults, where the hanging wall is downthrown and the footwall is upthrown. The faults typically dip toward the center of the graben from both sides. Horsts are parallel blocks that remain between graben; the bounding faults of a horst typically dip away from the center line of the horst.
Single or multiple graben can produce a rift valley.
One of the world's deepest graben with over 1000 metres of downthrow is the Mount Unzen volcanic complex in southern Japan.
In many rifts the graben are asymmetric, with a major fault along only one of the boundaries, and these are known as half-graben. The polarity (throw direction) of the main bounding faults typically alternate along the length of the rift. The asymmetry of a half-graben strongly affects syntectonic deposition. Comparatively little sediment enters the half-graben across the main bounding fault, due to the effects of footwall uplift on the drainage systems. The exception is at any major offset in the bounding fault, where a relay ramp may provide an important sediment input point. Most of the sediment will enter the half-graben down the unfaulted hanging wall side (e.g. Lake Baikal).[3]
Ukraine, India, China, Turkey, United Kingdom
San Francisco Bay Area, San Jose, California, Arizona, Sacramento, California, Los Angeles
Ontario, Quebec City, Quebec, Ottawa, Aboriginal peoples in Canada
Venus, Graben, Corona (planetary geology), Basalt, Shield volcano
Uranus, Moon, Moons of Uranus, Miranda (moon), Umbriel (moon)
Tharsis quadrangle, Graben, Lunae Palus quadrangle, Solar system, Latin
Portugal, Azores, Água de Pau Massif, Portuguese language, Graben