Drumlins

1
Drumlins
Theories and experiments as presented in The
Origin of Glacially Fluted Surfaces -
Observations and Theories By G.S. Bolton and
Drumlin Formation Time Evidence from Northern
and Central Sweden By Huattestrand et al.

• The Forming of A Landscape
• By Matthew OHare

2
What are Drumlins

• The word drumlin comes form the Irish word druim.
• Drumlins are made up of sediment deposited by a
  glacier.
• Swarms of drumlins have shaped the geography of
  many areas around the world.

3
Form of Drumlins
4
Introduction to The Origin of Glacially Fluted
Surfaces

• Disputes existing theories of tunnels causing
  drumlins
• Proposes new theory involving pressure
  differences caused by obstructions
• Flutes similar to shear marks

5
Method and Research of Boulton

• 13 glaciers
• Height of obstruction important
• Subglacial observations
• Till-fabric measurements
• Folding

6
Theory
The Formation of Individual Flutes

• Cavities will tend to occur when
• Flute sizes depend on the stresses surrounding
  it.
• Rejects frozen till hypothesis

7
Interrelationship Between Flutes on Fluted
Surfaces

• Claims ideas are erroneous of rhythmic mechanism
  to spacing of flutes.
• Depends on number of boulders in glacier
• Flutes interact to form different shapes

8
Conclusions of Boulton