Roche moutonnée

Roche moutonnée

In glaciology, a roche moutonnée (or sheepback) is a rock formation created by the passing of a glacier. When a glacier erodes down to bedrock, it can form tear-drop shaped hills that taper in the direction of flow.

The appearance of the erosional glacier feature is very defined: a rock formation where all the sides and edges have been smoothed and eroded in the direction of the glacier that once passed over it, with the exception of the rough and craggy opposite side. It is this side that has been subjected to "plucking", the erosional process in which ice melts slightly by pressure and seeps into cracks in the rock. When the water freezes, the rock is attached to the glacier and eventually ripped away from the landform as the glacier continues its forward progress. It is also subjected to frost shattering.

The term "roche moutonnée" comes from the French for "fleecy rock", despite its popular misinterpretation as "rock sheep". They are often marked with glacial striations.

Note that the side profile of a roche moutonnée is opposite to that of a drumlin. In a drumlin, the steep side is "facing" the approaching glacier, rather than "trailing" it.

ee also

*Glacial landforms

References

* cite book
last = Tarbuck
first = E.J.
authorlink =
coauthors = F.K. Lutgens
title = Earth: An Introduction to Physical Geography, 7th ed.
publisher = Prentice Hall
date = 2002
location = Upper Saddle River, NJ
pages = 342
url =
doi =
id = ISBN 0-13-092025-8

* cite book
last = Trenhaile
first = Alan
authorlink =
coauthors =
title = Geomorphology: A Canadian Perspective
publisher = Oxford University Press
date = 2007
location = Don Mills, Ontario
pages = 180-1
url =
doi =
id = ISBN 0-19-542474-3


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Look at other dictionaries:

  • Roche moutonnée — Une roche moutonnée est, en glaciologie, une formation rocheuse altérée par le passage d un glacier. Ce dernier donne une forme convexe, tronquée et parfois striée à la roche[1] …   Wikipédia en Français

  • Roche moutonnée — ● Roche moutonnée roche en forme de mamelon, usée et polie par le frottement d un glacier …   Encyclopédie Universelle

  • roche moutonnée — [rō̂sh mo͞o tō̂ nā′] [Fr, sheep shaped rock] n. Geol. a bare hummock of rock, usually smoothed on the upstream side and grooved on the other by glacial action …   English World dictionary

  • roche moutonnée — /rohsh mooht n ay /; Fr. /rddawsh mooh taw nay /, Geol. a rounded, glacially eroded rock outcrop, usually one of a group, resembling a sheep s back. Also called sheepback rock. [1835 45; < F: glaciated rock, lit., fleecy rock] * * * ▪ geology… …   Universalium

  • roche moutonnée — roche mou•ton•née [[t]ˈroʊʃ ˌmut nˈeɪ[/t]] n. gel a rounded, glacially eroded rock outcrop, usu. one of a group, resembling a sheep s back • Etymology: 1835–45; < F: lit., fleecy rock …   From formal English to slang

  • roche moutonnée — noun (plural roches moutonnées) Etymology: French, literally, fleecy rock Date: 1843 an elongate rounded ice sculptured hillock of bedrock …   New Collegiate Dictionary

  • roche moutonnee —    A small elongate protruding knob or hillock of bedrock, so sculptured by a large glacier as to have its long axis oriented in the direction of ice movement, an upstream (stoss or scour) side that is gently inclined, smoothly rounded, and… …   Glossary of landform and geologic terms

  • roche moutonnée — [ˌrɒʃ mu: tɒneɪ] noun (plural roches moutonnées pronunciation same) Geology a small bare outcrop of rock shaped by glacial erosion, with one side smooth and gently sloping and the other steep, rough, and irregular. Origin C19: Fr., lit. fleecy… …   English new terms dictionary

  • roche moutonnée — /rɔʃ mutəˈneɪ/ (say rawsh moohtuh nay) noun (plural roches moutonnées /rɔʃ mutəˈneɪ/ (say rawsh moohtuh nay)) a knob or rock rounded and smoothed by glacial action. {French} …  

  • roche moutonnée —   n. n. (pl.    ♦ roches moutonnées pron. same) sheep like rock ; rock rounded by glacial action …   Dictionary of difficult words

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