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Glacial plucking is most significant where the rock surface is well jointed or fractured or where it contains exposed bed planes, as this allows meltwater and clasts to penetrate more easily. [2] Plucking of bedrock also occurs in steep upland rivers, and shares a number of similarities with glacial examples.
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. [9] Abrasion can crush smaller grains or particles and remove grains or multigrain fragments, but the removal of larger fragments is classified as plucking (or ...
Chatter marks on sandstone south of Lac Beauchamp, in Gatineau, Quebec, Canada. In glacial geology, a chatter mark is a wedge-shaped mark (usually of a series of such marks) left by chipping of a bedrock surface by rock fragments carried in the base of a glacier (glacial plucking).
Terminal moraine of Wordie Glacier, Greenland Map of the Salpausselkä terminal moraines in Southern Finland. A terminal moraine, also called an end moraine, is a type of moraine that forms at the terminal (edge) of a glacier, marking its maximum advance.
Fluvioglacial deposits differ from glacial till in that they were deposited by means of water, rather than the glacial itself, and the sediments are thus also more size sorted than glacial till is. The stone walls of New England contain many glacial erratics, rocks that were dragged by a glacier many miles from their bedrock origin.
The Lower Curtis Glacier in North Cascades National Park is a well-developed cirque glacier; if the glacier continues to retreat and melt away, a lake may form in the basin Eventually, the hollow may become a large bowl shape in the side of the mountain, with the headwall being weathered by ice segregation, and as well as being eroded by plucking .
Glacial drift is a general term for the coarsely graded and extremely heterogeneous sediments of glacial origin. Glacial till is that part of glacial drift which was deposited directly by the glacier. tillite A type of sedimentary rock derived from glacial till which has been indurated or lithified by subsequent burial into solid rock. titanite
As mountains grow higher, they generally allow for more glacial activity (especially in the accumulation zone above the glacial equilibrium line altitude), [38] which causes increased rates of erosion of the mountain, decreasing mass faster than isostatic rebound can add to the mountain. [39] This provides a good example of a negative feedback ...