Stratigraphic ridge found in Northeastern Tennessee

A ridge is a geological feature that features a continuous elevational crest for some distance. Tennessee ( is a state located in the Southern United States. Ridges are usually termed hills or mountains as well, depending on size. A mountain is a Landform that extends above the surrounding Terrain in a limited area with a peak There are several main types of ridges:

• Dendritic ridge: In a typical plateau terrain, the stream drainage valleys will leave intervening ridges. These are by far the most common ridges. These ridges usually represent slightly harder rock, but not always -- they are often simply because there were larger joint spaces 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, very long, very even, very straight ridges are formed due to the fact that they're the uneroded remaining edges of the more resistant strata that were folded laterally. The Ridge-and-Valley Appalachians, also called the Ridge and Valley Province or the Valley and Ridge Appalachians, are a physiographic province of Similar ridges have formed in places such as the Black Hills, where the ridges form concentric circles around the igneous core. The Black Hills ( Pahá Sápa in Lakota, Moˀȯhta-voˀhonáaeva in Cheyenne) are a small isolated Mountain range rising from the Igneous rocks (etymology from Latin ignis, fire are rocks formed by solidification of cooled Magma (molten rock 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. This article discusses the geologic usage for the philosophical or architectural usage see Architectonics ' Or see Plate tectonics. The Mid-Atlantic Ridge (MAR is a Mid-ocean ridge, a Divergent tectonic plate boundary located along the floor of the Atlantic Ocean. 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. A meteorite is a natural object originating in Outer space that survives an impact with the Earth 's surface In the broadest sense the term impact crater can be applied to any depression natural or manmade resulting from the high velocity impact of a projectile with larger body

• Volcanic caldera ridges: Large volcanoes often leave collapsed central calderas that are bordered by circular ridges. Plate tectonics and hotspots Divergent plate boundaries At the A caldera is a cauldron-like volcanic feature formed by the collapse of land following a volcanic eruption

• Thrust fault ridges: Thrust faults often form escarpments. A thrust fault is a type of fault, or break in the Earth's crust with resulting movement of each side against the other in which a lower stratigraphic position is pushed up In Geomorphology, an escarpment is a transition zone between different physiogeographic provinces that involves a sharp steep Elevation differential characterized 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. In physical Geography, a dune is a Hill of Sand built by Aeolian processes. Sand is a naturally occurring Granular material composed of finely divided rock and Mineral particles

• Moraines and eskers: Glacial activity may leave ridges in the form of moraines and eskers. "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. Moraine refers to any glacially formed accumulation of unconsolidated glacial debris (soil and rock which can occur in currently glaciated and formerly glaciated regions such as those An esker is a long winding ridge of Stratified Sand and Gravel, examples of which occur in glaciated and formerly glaciated regions of An arête is a thin ridge of rock that is formed by glaciers.

• Volcanic subglacial ridges: Many subglacial volcanoes create ridge-like formations when lava erupts through a thick glacier or ice sheet. A subglacial volcano is a volcanic form produced by Subglacial eruptions or eruptions beneath the surface of a Glacier or Ice sheet which is then melted "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. An ice sheet is a mass of Glacier Ice that covers surrounding terrain and is greater than 50000 km² (20000 mile²)

See also

• Tectonic uplift

External links

• InterRidge An initiative for international cooperation in ridge-crest studies