2a.Landforms - Erosional

Question 1

Erosional landforms

Answer 1

• Corries
• Aretes / pyramidal peaks
• Troughs
• Roche moutonnees / striations
• Ellipsodial basins
• Tarn
• Hanging valley
• Ribbon Lake

Question 2

Aretes / pyramidal peeks

Answer 2

• Arete narrow steep sided ridge (knife edge)
• Form from erosion from corries
• 200 - 300m high (almost vertical)
• Pyramidal peek, 2 or more corries develop to form pyramid
• Further weathering sharpens shape

Question 3

Troughs

Answer 3

• Glaciers erode valley sides / floor
• Deepens, widens, straightens shape
• Described as u shape / parabolic

Question 4

Corries

Answer 4

• Arm chair shaped hollows on upland hills or mountains
• Steep back wall with a frontal lip
• solid or made of morainic deposits
• vary in size (some over 15k wide): 2.8:1 & 3.2:1

-Form via nivation of small hollow which accumulates snow
-Hollow enlarges, ice causes rotational movement under weight (creates lip)
This causes plucking at the back (steep)
-Debris helps to abrade hollow

Question 5

Roche moutonnees / striations

Answer 5

-Resistant rock causes localised pressure as ice passes over them
-Area is smoothed by abrasion
-Striations formed (scratches / grooves)
pressure reduced down valley, plucking takes place, water refreezes

Question 6

Ellipsoidal basins

Answer 6

• Created from ice sheets via erosion
• Contains lakes
• Major erosional landforms