scratches in rock produced by glacial abrasion are called fault breccia.
scratches in rock produced by glacial abrasion are called fault breccia.
scratches in rock produced by glacial abrasion are called?
fault breccia
glacial abrasion is the surface wear achieved by individual clasts, or rocks of various sizes, contained within ice or by subglacial sediment as the glacier slides over bedrock (krabbendam & glasser 2011). abrasion can crush smaller grains or particles and remove grains or multigrain fragments, but the removal of larger fragments is classified as plucking (or quarrying), the other major erosion source from glaciers. plucking creates the debris at the base or sides of the glacier that causes abrasion. while plucking has generally been thought of as a greater force of geomorphological change, there is evidence that in softer rocks with wide joint spacing that abrasion can be just as efficient. a smooth, polished surface is left behind by glacial abrasion, sometimes with glacial striations, which provide information about the mechanics of abrasion under temperate glaciers
abrasion (geology)
cirques form in conditions which are favorable; in the northern hemisphere the conditions include the north-east slope where they are protected from the majority of the sun's energy and from the prevailing winds. these areas are sheltered from heat, encouraging the accumulation of snow; if the accumulation of snow increases, the snow turns into glacial ice. the process of nivation follows, whereby a hollow in a slope may be enlarged by ice segregation weathering and glacial erosion. ice segregation erodes the rock vertical rock face and causes it to disintegrate, which may result in an avalanche bringing down more snow and rock to add to the growing glacier. eventually, this hollow may become large enough that glacial erosion intensifies. the enlarging of this open ended concavity creates a larger leeward deposition zone, furthering the process of glaciation. debris (or till) in the ice also may abrade (glacial abrasion) the bed surface; should ice move down a slope it would have a ‘sandpaper effect’ on the bedrock beneath, on which it scrapes.
cirque