(geology) the mechanical process of wearing or grinding something down (as by particles washing over it).
form at high elevations where temperatures remain cold enough during the summer to keep the previous winter's snow from melting allowing snow and ice to accumulate., A glacier confined to a mountain valley, which in most instances had previously been a stream valley.
Type of mass movement that involves the detachment and movement of a small block of rock from a cliff face to its base. Normally occurs when the rock has well defined bedding planes that are exaggerated by freeze-thaw action or thermal expansion and contraction.
A downslope movement of rock and soil over a failure surface and under the influence of gravity. Slumps, earthflows, debris flows and debris slides are examples.