What is a drumlin?
Drumlins are asymmetrical hills made of poorly sorted till. They typically have one very steep side and one more gradually sloping side which indicates the direction the glacier moved. They are typically found in groups.
How does a drumlin form?
A drumlin forms when the glacier bulldozes a pile of sediment (till) forward as it advances. This is what forms the steep side of the drumlin. Eventually, the glacier continues to move forward, but instead of continuing the bulldozing motion, the glacier slides down the other side of the pile, forming the less steep side of the drumlin. However, this is not the only way in which a drumlin’s gradual side is formed. It can also be created if the glacier stops moving after it bulldozes the material, and instead, meltwater runs down the snout, smoothing the other side of the drumlin.
Where do drumlins form?
Drumlins form at the snouts of glaciers, where the sediment is being pushed forward.
Other interesting facts:
The word drumlin comes from the Gaelic word drum, meaning “little ridge”. This feature was first named by Maxwell Henry Close, an Irish geologist and clergyman, who studied the glaciers in Ireland in the 1800s.
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Drumlin Formation. Digital image. East Lothian Landscapes. N.p., n.d. Web. 26 May 2013. <http://www.landforms.eu/Lothian/images/drumlin.jpg>.
Morley Bow Valley, Alberta. Digital image. Vincent Massey Junior High School. N.p., Feb. 2002. Web. 26 May 2013. <http://dnowlan.ca/VM/science7/planetearth/drumlin.jpg>.