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Zone of plucking in the formation of tarns and cirques Glacially-plucked granitic bedrock near Mariehamn, Åland. Plucking, also referred to as quarrying, is a glacial phenomenon that is responsible for the weathering and erosion of pieces of bedrock, especially large "joint blocks". This occurs in a type of glacier called a
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 ...
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). Marks tend to be crescent-shaped and oriented at right angles to the direction of ice movement. [1] [2]
The accumulation of till will form a terminal moraine as the glacier retreats. [2] Ablation moraines form when a large piece of ice, containing an accumulation of sediment and debris, breaks from the snout of the glacial. Once it is separated and begins to melt, the debris found throughout this glacial piece is deposited to form a new terminal ...
Glacial outwash sediment, Knud Rasmussen Glacier, Greenland. An outwash fan is a fan-shaped body of sediments deposited by braided streams from a melting glacier.Sediment locked within the ice of the glacier gets transported by the streams of meltwater, and deposits on the outwash plain, at the terminus of the glacier.
Erosion under a glacier in the immediate vicinity of a drumlin can be on the order of a meter's depth of sediment per year, depending heavily on the shear stress acting on the ground below the glacier from the weight of the glacier itself, with the eroded sediment forming a drumlin as it is repositioned and deposited. [8]
If the glacial action erodes through, a spillway (or col) forms; Horn: a sharp peak connecting multiple glacier intersections, made up of multiple arêtes. Valley step: an abrupt change in the longitudinal slope of a glacial valley; Hanging Valleys: Formed by glacial meltwater eroding the land partially, often accompanied by a waterfall. [2]
Till is a form of glacial drift, which is rock material transported by a glacier and deposited directly from the ice or from running water emerging from the ice. [1] It is distinguished from other forms of drift in that it is deposited directly by glaciers without being reworked by meltwater.