Erosional/Depositional landforms Flashcards
What are Corries?
Corries form when snow continues to build up in a hollow compacting to form a glacier. The glacier becomes trapped in the hollow and can only move by rotational slip. The back wall is eroded and the hollow is deepened through this process.
What are Aretes?
A sharp-edged ridge formed between two corries. When three meet they create a pyramidal peak
What are glacial troughs?
A u-shaped valley formed by a glacier eroding through a river. The glacier has enough force to erode away arivers interlocking spurs
What are hanging valleys?
A hanging valley is a smaller side valley left ‘hanging’ above the main U-shaped valley formed by a tributary glacier. The smaller glacier does not have enough energy to erode to the valley floor
What is a drumlin?
When a glacier hits an obstacle that cannot be eroded, deposition from underneath the glacier builds up behind the obstacle. Glacier moves over mound and drags excess deposition over the other side.
What is an arete?
A steep sided ridge formed when two glaciers flow in parallel valleys. The glaciers erode the sides of the valley, sharpening the mountain ridge between them
What are truncated spurs?
Formed when ridges of land stick out into the main valley are chopped off as the main valley glacier moves past
What is a tarn?
A lake that forms in corries after a glacier has retreated
What is a roche moutonnee?
A resistant mass of rock on the valley floor
The upstream side is smooth and gently sloping and the downstream side is rough and steep
What is an Erratic?
A boulder that’s been picked up and carried along and dropped in an area of different geology
Name 6 erosional Erosional landforms
Corries, Aretes, Glacial troughs, Hanging valleys, Truncated spurs, Roches moutonnees
Name 4 depositional landforms
Drumlins, erracits, moraines and till plains
What is a moraine?
Sediment transported beneath a glacier, resulting in poorly sorted angular sediments
What is a ground moraine?
Sediment transported beneath a glacier, simply smeared over underlying bedrock, often several metres thick and forming irregular surface topography
What is a terminal moraine?
A ridge of sediment piled up at the furthest extent of an advancing glacier. They often appear as a line of hills rather than a continuous ridge
What is a recessional moraine?
A retreating glacier often experiences periods of stability during which a secondary ridge forms at its snout having the same characteristics as a terminal moraine
What is a Lateral moraine?
A high, almost symmetrical ridge formed alongside a glacier from build up of scree-slopes
What is a Medial moraine?
When two glaciers merge, lateral moraines at the edges of the two glaciers join to form a medial moraine
What is a till plain?
An extensive plain resulting from melting of a large sheet of ice that became detached from a glacier
