Geomorpholoical Landforms Flashcards
Corries
Deep hollows caused when a small glacier
develops in a depression. Through rotational
slip and erosion of the back wall, the hollow
is deepend into a corrie. Water can fill corries
to make tarns (lakes).
Arêtes
A knife-edged ridge formed between two
corries. Erosion (abrasion and plucking) of
the steep back wall leaves the edge
remaining.
Glacial Troughs
A u-shaped valley formed by a glacier
bulldozing and eroding through a river
(v-shaped) valley. This leaves smooth but
steep truncated spurs on the valley sides
and a wide, flat valley floor.
Hanging Valleys
A smaller u-shaped valley caused by a
tributary glacier. The smaller glacier does
not have enough energy to erode to the
valley floor, leaving a hanging valley.
Waterfalls often form here.
Roches moutonnées
A mound of rock shaped by a glacier flowing
over it and eroding it. The glacier would be
moving right to left in the picture. The
glacier hits a large, hard rock. It abrades
one side as it moves onto the rock, and
plucks the other going over it.
Drumlins
When a glacier hits an obstacle that cannot
be eroded, deposition from underneath the
glacier builds up behind the obstacle. The
glacier moves over the large mound and
then drags excess deposition over the other
side. This causes a tear drop shape with a
long, tapered edge.
Erratics
A large boulder that is of a different rock
type to surrounding rock. Theoretically, this
boulder would have been broken off by
weathering and erosion, then transported
by a glacier and deposited when it has
been moved to a different location. The
glacier deposits when it loses energy.
Moraines
Deposits of eroded material that is
transported with the glacier. There are
different types of moraine:
Lateral moraine:
material deposited on the sides of
a glacier, leaving a ridge when the ice melts
Medial moraine:
formed from two lateral moraines
meeting in the middle of a glacier and
depositing material.
Recessional moraine:
Forms at the end of a glacier
when a retreating glacier stays stationary
for a sufficient time. Usually shows smaller,
seasonal retreats.
Terminal moraine:
Material deposited at the snout
of a glacier on the valley floor.
Till Plains
Till is unsorted glacial material formed
through erosion and weathering. Till
plains form when an ice sheet detaches
from the main glacier and melts, causing all
of the till on top of and within the glacier to
deposit on the valley floor
