Glacial Processes and Features

Glacial erosion landforms

Features formed by abrasion and plucking.

Corries

Large, hollowed-out depressions found on the upper slopes of glaciated valleys. The features of Corries include a steep back wall and a raised lip at the front.

Tarn

Small mountain lake or pool formed in a corrie.

Arete

A narrow, knifelike ridge separating two adjacent glaciated valleys.

Pyramidal Peak

Where several corries cut back to meet at a central point, the mountain takes the form of a steep pyramid.

Truncated spur

An eroded interlocking spur characterised by having a very steep cliff.

Glacial Trough

A U-shaped mountain valley that has been widened, deepened, and straightened by a glacier

Ribbon lake

A long, narrow lake in the bottom of a glacial trough

Hanging Valley

A valley left by a melted tributary glacier that enters a larger glacial valley above its base, high up on the valley wall.

Striations

Long parallel scars in rocks carved by rock fragments being dragged across them by a glacier.

Roche Moutonnee

Rounded knob of rock produced by glacial erosion

Glacial deposition

When a glacier melts, it deposits the sediment it eroded from the land, creating various landforms.

Erratic

A piece of rock that differs from the geology and size of rock native to the area in which it rests.

Drumlin

A long mound of till that is smoothed in the direction of the glacier's flow.

Medial moraine

A moraine formed when two advancing valley glaciers come together to form a single ice stream, forms in the middle of the glacier.

Recessional moraine

Marks the pauses in the retreat of a glacier.

Lateral moraine

Moraine that forms along the side of a glacier

Terminal moraine

A moraine deposited at the point of furthest advance of a glacier or ice sheet.

Erosion

Processes by which rock, sand, and soil are broken down and carried away (i.e. weathering, glaciation)

Freeze-thaw weathering

Weathering involving repeated cycles of freezing and thawing.

Frost Action

Breaks up rocks from repeated freezing and thawing of ice in cracks in rocks

Abrasion

The grinding away of rock by other rock particles carried in water, ice, or wind.

Plucking

The process by which a glacier picks up rocks as it flows over the land.

Rotational slip

Slippage of ice along a curved surface

Bulldozing

Ice pushes material of all shapes and sizes as it moves slowly forward.

Deposition

Process in which sediment is laid down in new locations.

Sediment

Small, solid pieces of material that come from rocks or living things

Till

The sediments deposited directly by a glacier

Moraine

Piles of rocky debris left by melting glaciers

Outwash

Material deposited by meltwater from a glacier