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Glacial striations are usually multiple, straight, and parallel, representing the movement of the glacier using rock fragments and sand grains, embedded in the base of the glacier, as cutting tools. Large amounts of coarse gravel and boulders carried along underneath the glacier provide the abrasive power to cut trough-like glacial grooves.
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 ...
Glacial abrasion is the weathering of bedrock below a flowing glacier by fragmented rock on the basal layer of the glacier. The two mechanisms of glacial abrasion are striation of the bedrock by coarse grains moved by the glacier, thus gouging the rock below, and polishing of the bedrock by smaller grains such as silts.
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]
The valley wall prevents meltwater streams from flowing outward away from the glacial snout. Instead, glacial meltwater is diverted laterally along the ice margin and deposits sediments between the glacier and valley wall. [25] As the glacier retreats, the process may repeat creating a stepped slope or terrace referred to as a kame terrace.
Glacial plucking both exploits pre-existing fractures in the bedrock and requires continued fracturing to maintain the cycle of erosion. [4] 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]
Glacier morphology, or the form a glacier takes, is influenced by temperature, precipitation, topography, and other factors. [1] The goal of glacial morphology is to gain a better understanding of glaciated landscapes and the way they are shaped. [ 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 ...