drumlin

drumlin
/drum"lin/, n. Geol.
a long, narrow or oval, smoothly rounded hill of unstratified glacial drift.
[1825-35; DRUM2 + -lin, var. of -LING1]

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      oval or elongated hill believed to have been formed by the streamlined movement of glacial ice sheets across rock debris, or till. The name is derived from the Gaelic word druim (“rounded hill,” or “mound”) and first appeared in 1833.

      Drumlins are generally found in broad lowland regions, with their long axes roughly parallel to the path of glacial flow. Although they come in a variety of shapes, the glacier side is always high and steep, while the lee side is smooth and tapers gently in the direction of ice movement. Drumlins can vary widely in size, with lengths from 1 to 2 km (0.6 to 1.2 miles), heights from 15 to 30 m (50 to 100 feet), and widths from 400 to 600 m.

      Most drumlins are composed of till, but they may vary greatly in their composition. Some contain significant amounts of gravels, whereas others are made up of rock underlying the surface till (rock drumlins). Drumlins are often associated with smaller, glacially streamlined bedrock forms known as roches moutonnées (roche moutonnée).

      Drumlins are commonly found in clusters numbering in the thousands. Often arranged in belts, they disrupt drainage so that small lakes and swamps may form between them. Large drumlin fields are located in central Wisconsin and in central New York; in northwestern Canada; in southwestern Nova Scotia; and in Ireland.

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Universalium. 2010.

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  • drumlin — [ drɶmlin ] n. m. • 1907; mot irland., du gaélique druim « bord d une colline » ♦ Géogr. Éminence elliptique constituée par les éléments d une moraine, dans les pays de relief glaciaire. ● drumlin nom masculin (anglais drumlin, du gaélique druim …   Encyclopédie Universelle

  • Drumlin — Drum lin, n. [Gael. druim the ridge of a hill.] (Geol.) A hill of compact, unstratified, glacial drift or till, usually elongate or oval, with the larger axis parallel to the former local glacial motion. [1913 Webster] …   The Collaborative International Dictionary of English

  • drumlin — (n.) 1833, dim. of drum (1725) ridge or long, narrow hill, often separating two parallel valleys, from Gael. & Ir. druim back, ridge …   Etymology dictionary

  • drumlin — [drum′lin] n. [< Ir druim, narrow ridge + lin, dim. suffix < LING1] any one of a series of low, flattened, oval mounds or hills formed by an advancing glacier …   English World dictionary

  • Drumlin — For the band, see Drumlin (band). Elongate and forested drumlins south of Puerto Williams, Chile. Flow direction here was at time of formation from west to east (left to right on picture) …   Wikipedia

  • Drumlin — Der auf einem Drumlin erbaute Ort Raderach Drumlins mit Baum im …   Deutsch Wikipedia

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  • Drumlin — Drụm|lin 〈m. 6; Geol.〉 linsenförmige Aufschüttung von Grundmoränenmaterial aus der Eiszeit [engl.; zu ir. druim „Hügel, Rücken“] * * * Drum|lin [ drʊmlɪn , engl.: drʌmlɪn ], der; s, s u. Drums [engl. drumlin, Vkl. von: drum, zu ir. gäl. druim =… …   Universal-Lexikon

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