l l Learning Objective l Depositional Features of Glaciers
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      The most widespread features of glacial deposition are moraines.Moraines are basically layers or ridges of till. There are four main types of moraines.End moraines and ground moraines are common to both alpine glaciers and ice sheets. End moraines form at the terminus of the glacier.As the glacier begins to recede, a layer of till is laid down, forming a gently undulating surface of ground moraine.This ground moraine can be ten to hundreds of meters thick, substantially altering the physical environment.Alpine or valley glaciers also form two other types of moraine.The sides of a valley glacier accumulate large quantities of debris from the valley walls.When the glacier melts, this material is left behind as ridges called lateral moraines.When two advancing valley glaciers come together to form a single flow, the till that once carried along their edges is now joined to form a medial moraine.