Deposits by Glaciers

1
Deposits by Glaciers

• 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
2
Moraines

• 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.

3
Moraines
4
Drumlins

• 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

5
Outwash Plains and Eskers

• 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.

6
Kames, Kettles and Deltas

• 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.

7
Lakes Made by Glaciers

• 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.