Drumlins

The Forming of A Landscape

By Matthew O’Hare

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 Ĥưattestrand et al.

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.

Form of Drumlins

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

Method and Research of Boulton

• 13 glaciers• Height of obstruction

important• Subglacial

observations• Till-fabric

measurements • Folding

Theory

• Cavities will tend to occur when:

• Flute sizes depend on the stresses surrounding it.

• Rejects frozen till hypothesis

The Formation of Individual Flutes

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

Conclusions of Boulton