definitions Flashcards
abrasion
the scraping of rocks against a surface, wearing it down
freeze-thaw weathering
when water freezes in cracks and expands breaking the rock apart
plucking
when rocks are ‘ripped’ or pulled off the ground as the glacier moves over them
arete
a sharp steep-sided mountain ridge
corrie/cirque
a bowl-shaped hollow, sometimes filled with water (a tarn)
hanging valley
a smaller valley which suddenly ends and drops into a bigger valley, sometimes containing a waterfall
u-shaped valley
has steep sides and a flat bottom, usually a carved out v-shaped river valley
deposition
when material (e.g. rocks) are dropped after being carried by a glacier
drumlin
a smooth hill, shaped like the back of a spoon
erratic
a large rock or boulder which does not belong in a place, brought there by a glacier
ground moraine
piles of rock of various shapes and sizes left behind in a valley from a melted glacier
terminal moraine
a pile of rocks of various shapes built up in a long hilly mound, marking where a glacier ended
till
a mixture of clay, sand, gravel and boulders deposited by a glacier
lateral moraine
ridge of material that runs along edges of glacier
deposited as ice melts and glacier shrinks
medial moraine
when glaciers meet two lateral moraines come together to form large ridge of material that runs through centre of valley
