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End moraine size and shape are determined by whether the glacier is advancing, receding or at equilibrium. The longer the terminus of the glacier stays in one place, the more debris accumulate in the moraine. There are two types of end moraines: terminal and recessional. Terminal moraines mark the maximum advance of the glacier.
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. At this point, debris that has accumulated by plucking and abrasion, has been pushed by the front edge of the ice, is driven no further and instead is deposited in an unsorted pile of sediment.
A recessional moraine is a ridge of deposited debris that occurs when the glacier is stationary for an extended length of time. [27] This occurs when a glacier meaning the glacier is in equilibrium or has halted during retreat . The occurrence of end moraines can be useful for determining a pattern of advance, retreat, and equilibrium of a ...
Moraine: Built up mound of glacial till along a spot on the glacier. Feature can be terminal (at the end of a glacier, showing how far the glacier extended), lateral (along the sides of a glacier), or medial (formed by the merger of lateral moraines from contributory glaciers). Types: Pulju, Rogen, Sevetti, terminal, Veiki
Medial moraines are formed when a glacier meets its tributary glacier and merge, and the lateral moraines of each coalesce to form a moraine in the middle of the combined glacier. Less apparent are ground moraines , also called glacial drift , which often blankets the surface underneath the glacier downslope from the equilibrium line.
Throughout the area concerned, the various glacial pulsations that have produced impressive moraine accumulations over time are clearly evident. Of particular note among these is the left lateral moraine of the ancient glacier, known as the Serra di Ivrea: this is the largest formation of its kind existing in Europe. [3]
Till is deposited as the terminal moraine, along the lateral and medial moraines and in the ground moraine of a glacier, and moraine is often conflated with till in older writings. [16] Till may also be deposited as drumlins and flutes, though some drumlins consist of a core of stratified sediments with only a cover of till. [17]
Multiple erratics on the terminal moraine of the Okanogan Lobe. The Cascade Mountains are in the background.. The term "erratic" is commonly used to refer to erratic blocks, which geologist Archibald Geikie describes as: "large masses of rock, often as big as a house, that have been transported by glacier ice, and have been lodged in a prominent position in the glacier valleys or have been ...