Moraine

See also: Moraine (homonymy)

A moraine is mineral a remains cluster transported by a Glacier or a tablecloth of ice. Certain moraines are observable during their transport, on or in the ice, others are deposited on the subjacent ground, traces of old glaciers: the rocks which are detached from the Montagne will generally be conveyed by the glacier and deposited when this one melts, with very the Altitude, from where a rock stacking.

Movement

In the image opposite,
  • the margins of the glacier carry lateral moraines made up of rocks torn off by the ice and the cycle freezing-cast iron (cryoclastie).
  • higher, of the lateral moraines joined in order to form medial moraines .
  • Invisible under the ice is the subglacial moraine , torn off bottom of the valley and crushed by the movement of the ice.
  • At the end downstream, these remainders of the rocks fall from the ice like a terminal moraine .
  • Sometimes, the face of the ice will advance again; by pushing the remains in front of, with the manner of a bulldozer. In this case, a thorough moraine will be found.
  • At the time of the retirement of the face of a glacier, a Icecap or a tablecloth of ice, the retirement stops from time to time, which causes the formation of a series of moraines of recession .

After the cast iron of the ice

periglacial Lexicon

At the time of the retirement of the face of the ice, which occurs when the ice melts more quickly than it is not replaced while running, the glares of the crashed to pieces rock are separated by rivers from cast iron. One then classifies them like sediments with water such as Esker S and Kame S. (See the diagram lexicon) But there remain about it sediments deposited directly by the melting ice. On the grounds covered formerly, tablecloths of ice, one finds layers of erratic argillaceous deposits very widespread which represent the subglacial moraine. With the line in advance maximum of a tablecloth of ice of formerly, it-there-have generally, a wrinkle of coarse sediment which represents the terminal moraine.

Means of accumulation

The moraine is a stacking of rubble and stones conveyed by a Glacier and which is found with its accesses. The moraine wants to also say the product of the glacial erosion, materials resulting from the work of the glacier.

The word moraine thus carries a double direction, because the origins of the moraine are of two kinds:

  • alien: all that the glacier receives on its surface (falls due to the cryoclastie for example). This moraine protects the glacier from the radiation of the sun ( cf . the Sea of ice)
    • indigenous
  • : materials produced by the work even of the glacier (crushing of its bed.)

References

Ben, D.I and Evans, D.J.A. Glaciers & Glaciation (1998) ISBN 0-340-58431-9

Random links:1869 in right | Arthur Witty | Taxi 4 | Epistolary novel | Guylain Mololo | Modèle_en_spirale