Denudation
Denudation - demolition of weathered material by plane washout and gravitational movements, and after their accumulation on the surface.The agents of denudation are: gravitational movement of the work flow of water (water erosion), groundwater and surface water (karst, suffusion), snow and ice (nivation, exaration), wind (deflation), surf (abrasion), living organisms (human).Denudation intensity determined by the amount of sediment to be submitted by rivers, glaciers per unit time.Denudation landforms are:
Ground
- Actually denudation
In a broad sense - the surface arising due to the cumulative effects of the whole complex of denudation processes (eg peneplain or different structurally-denudation forms.
In the narrowsense - the surface of the exposed due to gravitational movements and plane washout (columns, niches, cornices, canopies)
peneplain - slabovskholmlennaya plain formed during prolonged denudation in the territory of ancient mountains. For the first time this term was coined by the American geologist William Morris Davis, in the nineteenthcentury. The process of denudation took place in a humid climate (rainfall greater than can evaporate and be absorbed into the ground, because this is formed by many rivers and streams that increase erosion on the area).
Eaves - snow formation in the mountains arisingunder the influence of winds on the ridges and peaks.
Niche - dredging the bottom of the scarp scarp resulting from the ravages of the surf flow.
- Erosion - surface developed running water (valley erosion terraces, ledges).
lost - part of the thickness of rocks in the form of a stage prepared for the development of mineral deposits.
Erosion terrace - terrace, composed of bedrock and ceilings instrativnym a thin alluvium.This is the most ancient form of terraces, featuring a large height.
- Abrasion - developed sea and lake abrasion (benches, Bench, niche abrasion terraces).
abrasion terrace (Bench) - the coastal part of the surface of the seabed, worked out by abrasion.
- Ekzaratsionnye - worked out by glaciers (plains, troughs, mutton foreheads).
touching - ancient glacial valley in the region with a trough-shaped cross-profile, wide bottom and steep concave sides, which are connected with the activities of glaciers plowed.The longitudinal profile trough valleys generally have stepped shape where alternate pereuglublennye areas (pools vypahivaniya) with elevated rocky steps (bolts).
Mutton foreheads - rounded ledge formed by the action (movement) of the glacier.Several adjacent small mutton foreheads, sometimes called curly rocks.In Russia, widespread in the Baltic Shield (Kola Peninsula).The surface of the mutton foreheads is covered with a thin layer of turf and small debris, easy shifts under load and slippery because of the trickling water.
- Nival - started at the snow line (line), as a result of frost weathering (nivatsionnye niche cars, circuses).
Kara - a form of relief, representing the cup-shaped recess in the apical part of mountain slopes.Kara has vertical sidewalls and flat bottom, a glacier occupied with the accumulation of snow and firn.At the edge of the car located crossbars.
Circus - Basin in the mountains closing the upper end of the glacial valley.
- Deflationary - caused by wind (niches, the mesh cell, aeolian mushrooms, sor-deflationary depression).
Eolian mushrooms - a form of relief that occurs as a result of wind and corrosion.As wind moves the particles mainly in the surface, the lower portions of the rocks processed grind and stronger winds.So there are aeolian landforms resemble pillars or mushrooms on a thin stalk.
- Karst - emerged from the dissolution (Ponor, funnels, hollows, caves).
- Manmade - arose in the course of industrial activity (canals, mines, mounds).
Underwater
- Gravity (landslides).
- Erosion (underwater valleys, canyons).
Submarine canyons - the valley with steep slopes, cut into the continental shelf and continental slope.Some of them are underwater extension estuaries, while others are not relevant to the current rivers.From the mouth of the Ganges at 1,000 miles in the Bay of Bengal stretches underwater canyon width of 7 km and a depth of 70 m. River Canyon.Congo observed at a distance of 260 km to a depth of 2,150 m. From p.Hudson Canyon begins, stretching towards the sea almost 400 km.In the area of the Pacific coast of the US continental shelf is very narrow, and canyons are deep and have steep slopes.Monterey Canyon off the coast of California is sometimes compared to the Grand Canyon.
