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drumlin
drumlin A smooth, streamlined, oval-shaped land-form, one end of which is blunt and the other tapered. Drumlins may occur singly, but more commonly they are found within a large group, called a ‘drumlin field’ or ‘drumlin swarm’. Usually they are composed of till or boulder clay, but occasionally they are composed largely of solid rock (hence ‘rock drumlin’). They are believed to be formed beneath the outer zone of an expanding ice sheet, during a major advance: they result from the selective deposition of material that is then streamlined by the moving ice. The long axis of a drumlin lies parallel to the direction of the advance.
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Cite this article
MICHAEL ALLABY. "drumlin." A Dictionary of Ecology. 2004. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "drumlin." A Dictionary of Ecology. 2004. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O14-drumlin.html MICHAEL ALLABY. "drumlin." A Dictionary of Ecology. 2004. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O14-drumlin.html |
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drumlin
drumlin Smooth, streamlined, oval-shaped land-form, one end of which is blunt and the other tapered. Drumlins may occur singly, but more commonly they are found within a large group, called a ‘drumlin field’ or ‘drumlin swarm’. Usually they are composed of boulder clay, but occasionally they are made of solid rock (hence ‘rock drumlin’). They are believed to be formed beneath the outer zone of an expanding ice sheet, during a major advance: they result from the selective deposition of material that is then streamlined by the moving ice. The long axis of a drumlin lies parallel to the direction of the advance.
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Cite this article
AILSA ALLABY and MICHAEL ALLABY. "drumlin." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "drumlin." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O13-drumlin.html AILSA ALLABY and MICHAEL ALLABY. "drumlin." A Dictionary of Earth Sciences. 1999. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-drumlin.html |
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drumlin
drumlin , smooth oval hill of glacial drift , elongated in the direction of the movement of the ice that deposited it. Drumlins, which may be more than 150 ft (45 m) high and more than 1/2 mi (.8 km) long, are common in New York, Wisconsin, Canada, and Northern Ireland. |
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Cite this article
"drumlin." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. "drumlin." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1E1-drumlin.html "drumlin." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-drumlin.html |
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drumlin
drum·lin / ˈdrəmlin/ • n. Geol. a low oval mound or small hill, typically one of a group, consisting of compacted boulder clay molded by past glacial action. |
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Cite this article
"drumlin." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. "drumlin." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O999-drumlin.html "drumlin." The Oxford Pocket Dictionary of Current English. 2009. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-drumlin.html |
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