Drumlin Formation
By Michael Nelson
Abstract:
Drumlins are elongate glacial landforms which are widely distributed in glacial landscapes. For such ubiquitous features their origins are surprisingly contested. Martini et al (2001) considers drumlins are probably formed in more than one way. Recently, the drumlins of northern New York and southern Ontario have had much debate over their origins. Two very different hypotheses have surfaced in the creation of these drumlins. The first hypothesis, by Muller, proposes that the drumlins were created by ice streams from the glacier (Muller, 1974). The second hypothesis is from Shaw. Shaw argues the drumlins were created by tremendous melt water form glacial lakes (Shaw, 1990). Melting ice from the glacier built up and was dammed by ice. This created large lakes. The lakes suddenly released the water creating the drumlins.
Figure 1: a typical cross-section of a drumlin
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Map showing the Great Drumlin Fields located in Western New York
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Reference:
Boyce, J. I. and Eyles, N., 1991, Drumlins carved by deforming till streams below the Laurentide ice sheet, Geology, v. 19, p. 787-790.
Martini, P.I., Brookefield, M. E., and Sadura, S., 2001, Principles ofGlacial Geomorphology and Geology. Prentice Hall, Upper Saddle River, NJ, p. 110-130.
Muller, E.H., 1974, Origin of Drumlins, in Coates, D.R., ed., Glacial geomorphology: Annual Geomorphology Symposium, 5th, State University of New York at Bingahamton, p. 187-204.
Muller, E. H. and Pair, D. L., 1992, Comment and Reply: Evidence for large-scale subglacial meltwater flood events in southern Ontario and northern New York State: Geology, v. 18, p. 90-92.
Shaw, John, and Gilbert, Robert, 1990, Evidence for large-scale subglacial melt water flood events in southern Ontario and northern New York State: Geology, v. 18 p. 1169-1172.
Shaw, John, 1989, Drumlins, subglacial meltwater floods, and ocean responses: Geology, v. 17 p. 853-856.