Glacial Erosion Features
Feature
Description
Formation
Corrie
Armchair shaped depression in
mountain side with steep back wall
and a rock lip.
Frost shattering, abrasion, plucking and
rotational ice movement.
Arête
Narrow knife edge ridge
Two corries cut back towards each
other.
Pyramidal
Peak
Pointed peak with radiating arêtes.
Three or more corries cutting
backwards.
U Shaped
Valley
Steep sided flat floored valley
Widened and deepened by valley
glacier.
Hanging
Valley
Tributary valley left high above the
main valley.
Ice in main valley eroded more rapidly
than ice in tributary valley
Truncated
Spur
Steep cliff like valley sides.
Valley glacier has removed the ends of
spurs by abrasion.
Rock
Step
Stepped long profile in a U shaped
valley.
Formed by more resistant rock on
valley floor resisting over deepening.
Ribbon
Lake
Long narrow lake in glacial trough.
Glacier over deepens valley floor.
Tarn
Small deep circular lake.
Over deepening by abrasion and
rotational movement. Fills with water
after ice melts.
Roche
Moutonnee
Ice smoothed rocks with a steeper
side facing down valley.
Resistant rock remains after abrasion
on the up valley side and plucking on the
lee side.
Striations
Rock scarred with parallel
scratches.
Moraine dragged along exposed rock.