Transcript Deposits by Glaciers

Deposits by Glaciers
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Most of the material carried by glaciers is
deposited by melting, called drift.
2 kinds of drift:
Till is left under or along the sides of a
moving glacier
Outwash is deposits from meltwater
Till at the edge of a glacier
Glacial outwash plain
Moraines
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The ground moraine forms a thin, fairly
even deposit over the area of the glacier.
Lateral and medial moraines form ridges
The end moraine forms a ridge at the ice
front, when a glacier recedes, recessional
moraines form.
The terminal moraine marks the glaciers
farthest advance
Large glacial boulders are called erratics.
Moraines
Drumlins
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Drumlins are long, smooth canoe-shaped
hills made of till, typically 400 m long, 100
m wide, 25 m high.
Likely formed when a glacier swept over a
previous moraine
Outwash Plains and Eskers
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Outwash plains look like alluvial fans made
up of deposits from meltwater at the ice
front.
Subglacial streams leave deposits as
winding ridges called Eskers.
Kames, Kettles and Deltas
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Kames are small cone-shaped hills of
stratified sand and gravel, formed by
stream deposits
Kettles are circular hollows found on
terminal plains and outwash plains, formed
by melting blocks of buried ice.
Deltas may form when glacial streams
empty into lakes.
Lakes Made by Glaciers
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Glaciation leaves new basins or depressions
in the land surface
These may fill with water to form lakes,
ponds, or swamps.
Types of lakes: Cirque lakes, Kettle lakes,
Moraine dammed lakes, Valley scoured
lakes.