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Abrasion, under its strictest definition, is commonly confused with attrition and sometimes hydraulic action however, the latter less commonly so. Both abrasion and attrition refers to the wearing down of an object. Abrasion occurs as a result of two surfaces rubbing against each other, resulting in the wearing down of one or both of the surfaces.
Abrasion occurs in natural environments such as beaches, sand dunes, river or stream beds by the action of current flow, wave impact, glacial action, wind, gravitational creep and other erosive agents. Recent studies have demonstrated that aeolian processes are more efficient in the rounding of sedimentary grains.
A continued supply of abrading fragments is required to uphold a similar level of abrasion. The fragments must be harder than the bedrock. Quartz fragments will abrade shale but shale fragments will not abrade a quartz rich bedrock. A constant flow of meltwater between the basal surface and the bedrock speeds abrasion.
Hydraulic action, most generally, is the ability of moving water (flowing or waves) to dislodge and transport rock particles.This includes a number of specific erosional processes, including abrasion, at facilitated erosion, such as static erosion where water leaches salts and floats off organic material from unconsolidated sediments, and from chemical erosion more often called chemical ...
A valley glacier cannot avoid the interlocking spurs as a river can. As the valley glacier moves, abrasion and plucking erode the protruding tips of the spurs, leaving steep cliff-like truncated spurs. Hanging valleys are found in between truncated spurs as they join the main glacial valley from the side. It is common for waterfalls to form ...
Deflation and abrasion are specific means of sediment transport than can also be attributed to aeolian processes. Deflation, which is named for the Latin word "deflare" meaning "to blow away", refers to the scattering and removal of rock particles by wind. Deflation occurs in deserts where diverse particles dominate the surface.
Abrasion also produces rock flour which is visible in glacial outwash plains across New England. Maine has some of the longest eskers in the world. [12] As the climate began to warm, the glaciers began to melt and drainage from meltwater under the glacier formed huge torrents of sediment that, when compacted, left a long and sinuous ridge or kame.
The ablation zone is found at the lowest altitude of the glacier, where ablation of material is lesser than accumulation. Ablation zone or ablation area refers to the low-altitude area of a glacier or ice sheet below firn with a net loss in ice mass.