plucking and abrasion deepen widen and straighten the valley
after glaciation a steep-sided flat bottomed valley is left
if the valley had inter locking spurs they will have been
truncated
often a mis-fit stream or ribbon lake is found on the valley
floor
how was a corrie formed
snow gathers in holoow on north facing slope
glacier moves downhill by gravity
plucking steepens the back wall
abrasion deepens the hollow
rotational movement leads to rocklip where erosive power is least
after glaciation an arm chair shapped hollow is left, often with a corrie lochan or tarn
frost shattering continues on backwall casuing scree
how is an arete formed
two corrie seroding back to back
plucking narrows the distance between two backwalls
after glaciation, a narrow knife edge ridge seperates the two corries
this is known as an arete
how is a pyramidal peak formed
three or more corries eroding back to back on the same mountain
plucking narrows the distance between the back walls
after glaciation a pointed, horn shaped peak is left
frost shateering continues on summit
how is a hanging valley formed
glacier moves down a main v shaped valley
erodes by pucking and abrasion and the valley gets deeper and wider
a smaller glacier erodes a tributery valley
it is eroded less deeply
after glaciation the smaller valley is higgher than the main valley
a waterfall is often formed
how is terminal moraine formed
glacier picks up moraine and transports it
glacier melts and the moraine is deposited at the snout of the glacier
a ridge of angular, unsorted rocks is left
the ridge marks the furthest point the glacier reached
how is an outwash plain formed
formed when sorted sand and gravel is washed out of the glacier by meltwater (water melting from the glacier) and deposited as a large flat area in front of the terminal moraine
how are drumlins formed
drumlins are egg shaped mounds formed when the glacier moulds till beneath it, to form streamlined moulds
they have a steep blunt end (stoss) and a gently sloping end (lee)
the ice moved towards the pointed end (lee)
how is an esker formed
Eskers are formed by melt water from the glacier
Meltwater flows in tunnels beneath the glacier
Stream carries sand and gravel and when this is deposited it
fills up the tunnels
When ice melts a long meandering ridge is left in the shape