Ridge

A ridge is a geological feature consisting of a chain of mountains or hills that form a continuous elevated crest for some distance. Ridges are usually termed hills or mountains as well, depending on size. There are several main types of ridges:

  • Dendritic ridge: In typical dissected plateau terrain, the stream drainage valleys will leave intervening ridges. These are by far the most common ridges. These ridges usually represent slightly more erosion resistant rock, but not always – they often remain because there were more joints where the valleys formed, or other chance occurrences. This type of ridge is generally somewhat random in orientation, often changing direction frequently, often with knobs at intervals on the ridge top.
  • Stratigraphic ridge: In places such as the Ridge-and-valley Appalachians, long, even, straight ridges are formed because they are the uneroded remaining edges of the more resistant strata that were folded laterally. Similar ridges have formed in places such as the Black Hills, where the ridges form concentric circles around the igneous core. Sometimes these ridges are called "hogback ridges".
  • Oceanic spreading ridge: In tectonic spreading zones around the world, such as at the Mid-Atlantic Ridge, the volcanic activity forming new plate boundary forms volcanic ridges at the spreading zone. Isostatic settling and erosion gradually reduce the elevations moving away from the zone.
  • Crater ridges: Large meteorite strikes typically form large impact craters bordered by circular ridges.
  • Volcanic caldera ridges: Large volcanoes often leave collapsed central calderas that are bordered by circular ridges.
  • Fault ridges: Faults often form escarpments. Sometimes the tops of the escarpments form not plateaus, but slope back so that the edges of the escarpments form ridges.
  • Dune ridges: In areas of large-scale dune activity, certain types of dunes result in sand ridges.
  • Moraines and eskers: Glacial activity may leave ridges in the form of moraines and eskers. An arête is a thin ridge of rock that is formed by glacial erosion.
  • Volcanic subglacial ridges: Many subglacial volcanoes create ridgelike formations when lava erupts through a thick glacier or ice sheet.
  • Shutter ridges: A Shutter ridge is a ridge which has moved along a fault line, blocking or diverting drainage. Typically, a shutter ridge creates a valley corresponding to the alignment of the fault that produces it.

Other articles related to "ridge":

Crowley's Ridge
... Crowley's Ridge (also Crowleys Ridge) is an unusual geological formation that rises 250 to 550 feet (170 m) above the alluvial plain of the Mississippi embayment ... Most of the major cities of the Arkansas Delta region lie along Crowley's Ridge ... The ridge received its name from Benjamin Crowley, the first European settler to reach the area (near present day Paragould, Arkansas) sometime around 1820 ...
Crowley's Ridge - Fossils
... This region adjacent to the ridge is covered with thick deltaic soils and few fossils are found except in gravel pits ... Crowley's Ridge contains important exposures of fossiliferous Tertiary sediments and contains the only documented Miocene exposures in the state ... found within the city limits of Helena at the southern end of the ridge ...
Blue Ridge Scenic Railway
... The Blue Ridge Scenic Railway is a heritage railroad in northern Georgia ... Based in Blue Ridge, Georgia, United States it follows the former Marietta and North Georgia Railroad line along the Toccoa River north to McCaysville, Georgia ... The Blue Ridge Scenic Railway started operations in 1998, and celebrated its 10th anniversary in 2007 ...
Armagh - Townlands
... Drumadd (from Druim-fhad meaning "long ridge") Drumarg (from Druim Arg meaning "ridge of the chests" or Druim Fhairig meaning "ridge of the feasting/hospitality") Drumman More (from an Drumainn meaning "the ridge ...
Grand Teton - Climbing Routes
... route up the mountain is via the Upper Exum Ridge Route (II, 5.5) on the Exum Ridge, an exposed route first climbed by Glenn Exum, co-founder of Exum Mountain Guides ... with one wide step from the end of Wall Street Ledge to the Ridge comprising the first stretch of technical climbing ... The direct start of the Exum Ridge using the Lower Exum Ridge Route (III, 5.7,) is considered a mountaineering classic and is featured in the historic climbing text Fifty Classic Climbs of North America ...

Famous quotes containing the word ridge:

    All sound heard at the greatest possible distance produces one and the same effect, a vibration of the universal lyre, just as the intervening atmosphere makes a distant ridge of earth interesting to our eyes by the azure tint it imparts to it.
    Henry David Thoreau (1817–1862)

    The light passes
    from ridge to ridge,
    from flower to flower.
    Hilda Doolittle (1886–1961)

    The self-consciousness of Pine Ridge manifests itself at the village’s edge in such signs as “Drive Keerful,” “Don’t Hit Our Young ‘uns,” and “You-all Hurry Back”Mlocutions which nearly all Arkansas hill people use daily but would never dream of putting in print.
    —Administration in the State of Arka, U.S. public relief program (1935-1943)