3.5 LOWLAND GLACIAL LANDFORMS
Diagram 3.5a Lowland glacial landforms
drumlins
description - This is a large elongated mound of glacial
till. Drumlins often occur in groups ... hence the terms 'drumlin
swarm' and 'drumlin field'. Many of the 'half egg-shaped' hills
in South West Scotland are drumlins.
explanation - This landform is created by ice moulding
the ground moraine as it passes over it. The drumlin has an aerodynamic
shape with the rounder end pointing in the direction the ice
flowed from.
diagram - Examine Diagram 3.5a and the diagram below.
Diagram 3.5b The formation of drumlins
kettle holes
description - This is a small hollow on the landscape.
These are often filled with water (kettle lakes).
explanation - As the ice retreated, then often blocks
of the ice would break off and become bedded in the underlying
ground moraine. When this 'stagnant' ice melted, it left a depression
on the landscape which has often been filled in by post glacial
drainage.
diagram - Examine Diagram 3.5a
meltwater channels - These are river channels formed by enormous rivers flowing from the melting ice sheets (especially during the short summers when melting would be at its maximum). The small present day streams and rivers flowing along these channels are misfit rivers (eg the Kilmarnock Water where it flows through Kilmarnock Town Centre could not have carved such a large valley with its present day flow.
Diagram 3.5c The formation of ground moraine, terminal moraine and outwash plains.
outwash plains
description - These are vast fairly level areas located
to the 'front' of a terminal moraine.
explanation - As a glacier or ice sheet melted (ablated)
then the meltwater carried deposits of gravel, sand ,silt and
clay. The coarsest materials were deposited next to the terminal
moraine then the next coarsest and so on. We thus find zones
of each of these sediments in front of a terminal moraine.
diagram - Examine the following diagram.
