esker

/es"keuhr/, n. Geol.
a serpentine ridge of gravelly and sandy drift, believed to have been formed by streams under or in glacial ice.
[1850-55; < Ir eiscir ridge of mountains]

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also spelled  Eskar, or Eschar,  
 a long, narrow, winding ridge composed of stratified sand and gravel deposited by a subglacial or englacial meltwater stream. Eskers may range from 16 to 160 feet (5 to 50 m) in height, from 160 to 1,600 feet (500 m) in width, and a few hundred feet to tens of miles in length. They may occur unbroken or as detached segments. The sediment is sorted according to grain size, and cross-laminations that show only one flow direction commonly occur. Thus eskers are considered to be channel deposits (left by streams that flowed through tunnels in and below the ice) that were let down onto the ground surface as the glacier retreated. Esker formation presumably takes place after a glacier stagnates, because movement of the ice would likely spread the material and produce ground moraine. Notable areas of eskers are found in Maine, U.S.; Canada; Ireland; and Sweden. Because of ease of access, esker deposits often are quarried for their sand and gravel for construction purposes.

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Universalium. 2010.

Look at other dictionaries:

  • Esker — An esker is a long winding ridge of stratified sand and gravel, examples of which occur in glaciated and formerly glaciated regions of Europe and North America. Eskers are frequently several kilometres long and, because of their peculiar uniform… …   Wikipedia

  • Esker — Saltar a navegación, búsqueda Un esker o Ås es un depósito de aluviones que forman colinas de varios metros de altura, hasta un centenar de metros de anchura y hasta centenares de kilómetros de longitud, que siguen la dirección del lecho de un… …   Wikipedia Español

  • esker — ésker s. n. Trimis de siveco, 10.08.2004. Sursa: Dicţionar ortografic  ÉSKER s.n. (geol.) Creastă lungă şi sinuoasă formată din nisipuri şi pietrişuri aduse de torenţii glaciari. [< engl. esker < cuv. islandez]. Trimis de LauraGellner,… …   Dicționar Român

  • Esker — Ein Os (Wallberg oder Esker) ist eine bahndammähnliche Aufschüttung von geschichteten Schmelzwassersanden und kiesen, die während der Eiszeit unter dem Gletschereis gebildet wurde. Oser sind ein Bestandteil der Grundmoränenlandschaft.… …   Deutsch Wikipedia

  • esker — [ɛskɛʀ] n. m. ÉTYM. XXe; 1852, en angl.; mot gaélique, anc. irlandais eiscir. ❖ ♦ Géol. Dépôt glaciaire formant des éminences allongées à sommet plat. ⇒ Ôs. 0 Dans les chenaux sous glaciaires peuvent se déposer des alluvions fluviatiles,… …   Encyclopédie Universelle

  • esker — deposit left by a glacial stream, 1852, from Ir. eiscir ridge of gravel …   Etymology dictionary

  • esker — [es′kär΄, es′kəres′kər] n. [Ir eiscir, a ridge] a winding, narrow ridge of sand or gravel, probably deposited by a stream flowing in or under glacial ice: sometimes called eskar [es′kär΄, es′kər] …   English World dictionary

  • Esker — Les différentes formations glaciaires Esker dans l État de Washington, Ét …   Wikipédia en Français

  • Esker — ozas statusas T sritis ekologija ir aplinkotyra apibrėžtis Ilgas, siauras ir vingiuotas į pylimą panašus ledyninės kilmės kalvagūbris. Ilgis iki kelių dešimčių kilometrų, plotis nuo kelių dešimčių metrų iki 2–3 km, aukštis 20–50 m. Susidaręs iš… …   Ekologijos terminų aiškinamasis žodynas

  • esker — Eschar Es char, n. [Ir.] (Geol.) In Ireland, one of the continuous mounds or ridges of gravelly and sandy drift which extend for many miles over the surface of the country. Similar ridges in Scotland are called kames or kams. [Written also… …   The Collaborative International Dictionary of English

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