“moraine”的概念、定义、翻译、参考文献-科学参考

moraine

Geology and Earth Sciences

Term originally applied to the ridges of rock debris around Alpine glaciers. Subsequently its meaning has been widened to include all of the rock debris deposit. For example, ‘ground’ moraine may denote an irregularly undulating surface of till, glacial drift, or boulder clay; or it may describe the deposit itself. An ‘end’ or ‘terminal’ moraine is a ridge of glacially deposited material laid down at the leading edge of an active glacier. Its height is in the range 1–100 m, and it is accumulated by a combination of glacial dumping and pushing. A ‘recessional’ moraine is morphologically similar and is laid down at the terminus of a glacier during a period of still-stand that interrupts a long period of retreat of the ice margin. A ‘lateral’ moraine is a ridge of debris at the margin of a valley glacier and largely derived from rock fall. It is a prominent feature of many contemporary Alpine glaciers. A ‘medial’ moraine results from the merging of lateral moraines when two glaciers converge. A ‘washboard’ moraine is a single ridge in a closely spaced pattern (perhaps 9–12 per kilometre) and stands some 1–3 m above the adjacent depressions. It is found in the ‘end’ moraine belt. A ‘push’ moraine is a morainic ridge made of unconsolidated rock debris and pushed up by the snout of an advancing glacier. See also de geer moraine; fluted moraine; hummocky moraine.

Geography

The rocks, boulders, and debris that are carried and deposited by a glacier or ice sheet. Moraine is often partly stratified, since some may have been formed under water. Ablation moraine is common on retreating glaciers, and coarse, because meltwater has washed out finer particles. As the glacier shrinks, lateral moraines are deposited at the side of the glacier. Where two lateral moraines combine, a central, medial moraine may be formed. Ground moraine, also called a till sheet, is a blanket covering the ground. Other moraines have been moulded by ice parallel to the direction of ice movement. These include fluted moraines which are long ridges, possibly formed in the shelter of an obstruction; see Benn (1994) Sedimentol. 41. Drumlins are streamlined moraines. Dump moraines are ridges formed approximately transverse to flow from material delivered to the margin of a glacier by ice flow. They mark the stationary position of an ice margin. The size of dump moraines depends on the rate of ice flow and the debris content of the ice (Murray in J. Holden 2012). A hummocky moraine is a strongly undulating surface of ground moraine, with a relative relief of up to 10 m, and showing steep slopes, deep, enclosed depressions, and meltwater channels, which have formed from the meltout of supraglacial or englacial material. Boone and Eyles (2001) Geomorph. 38, 1 suggest that the growth and decay of ponds in repeated cycles of subglacial till failure and landform development can produce hummocks, but Lukas (2006) PPG 30, 6 notes that the term hummocky moraine can be problematic.
End moraines/terminal moraines are till ridges, usually less than 60 m high, marking the end of a glacier. In plan, they are crescentic, corresponding with the lobes of the glacier; a well-developed end moraine shows that the ice front was there for some time. Krzyszkowski (2002) Sed. Geol. 149, 3–4 argues that end moraines often constitute alluvial fans, formed at the ice margin by the redeposition of supraglacial material. See Dyke and Lavelle (2000) Canadian J. Earth Scis 37 on major end moraines in Canada.
Recessional moraines mark stages of stillstand during the retreat of the ice; a transverse moraine is a recessional if the up-glacier surface shows streamlining. Rogen moraines are fields of transverse moraines, 10–30 m in height, up to 1 km long, 100–300 m apart, and often linked by cross-ribs. Their origin is uncertain. De Geer moraines form where a glacier meets its proglacial lake, and consist of till, layered sand, and lake deposits (Evans et al. (2002) J. Quat. Sci. 17, 3). Push moraines occur when a glacier is retreating in the melt period but advancing in the cold season; see Krüger et al. (2002) Norwegian J. Geog. 56. Glaciohydraulic supercooling may aid the development of moraines created by melt-out from basal ice (Lawson et al. (1998) J. Glaciol. 44).

单词	moraine
释义	moraine Geology and Earth Sciences Term originally applied to the ridges of rock debris around Alpine glaciers. Subsequently its meaning has been widened to include all of the rock debris deposit. For example, ‘ground’ moraine may denote an irregularly undulating surface of till, glacial drift, or boulder clay; or it may describe the deposit itself. An ‘end’ or ‘terminal’ moraine is a ridge of glacially deposited material laid down at the leading edge of an active glacier. Its height is in the range 1–100 m, and it is accumulated by a combination of glacial dumping and pushing. A ‘recessional’ moraine is morphologically similar and is laid down at the terminus of a glacier during a period of still-stand that interrupts a long period of retreat of the ice margin. A ‘lateral’ moraine is a ridge of debris at the margin of a valley glacier and largely derived from rock fall. It is a prominent feature of many contemporary Alpine glaciers. A ‘medial’ moraine results from the merging of lateral moraines when two glaciers converge. A ‘washboard’ moraine is a single ridge in a closely spaced pattern (perhaps 9–12 per kilometre) and stands some 1–3 m above the adjacent depressions. It is found in the ‘end’ moraine belt. A ‘push’ moraine is a morainic ridge made of unconsolidated rock debris and pushed up by the snout of an advancing glacier. See also de geer moraine; fluted moraine; hummocky moraine. Geography The rocks, boulders, and debris that are carried and deposited by a glacier or ice sheet. Moraine is often partly stratified, since some may have been formed under water. Ablation moraine is common on retreating glaciers, and coarse, because meltwater has washed out finer particles. As the glacier shrinks, lateral moraines are deposited at the side of the glacier. Where two lateral moraines combine, a central, medial moraine may be formed. Ground moraine, also called a till sheet, is a blanket covering the ground. Other moraines have been moulded by ice parallel to the direction of ice movement. These include fluted moraines which are long ridges, possibly formed in the shelter of an obstruction; see Benn (1994) Sedimentol. 41. Drumlins are streamlined moraines. Dump moraines are ridges formed approximately transverse to flow from material delivered to the margin of a glacier by ice flow. They mark the stationary position of an ice margin. The size of dump moraines depends on the rate of ice flow and the debris content of the ice (Murray in J. Holden 2012). A hummocky moraine is a strongly undulating surface of ground moraine, with a relative relief of up to 10 m, and showing steep slopes, deep, enclosed depressions, and meltwater channels, which have formed from the meltout of supraglacial or englacial material. Boone and Eyles (2001) Geomorph. 38, 1 suggest that the growth and decay of ponds in repeated cycles of subglacial till failure and landform development can produce hummocks, but Lukas (2006) PPG 30, 6 notes that the term hummocky moraine can be problematic. End moraines/terminal moraines are till ridges, usually less than 60 m high, marking the end of a glacier. In plan, they are crescentic, corresponding with the lobes of the glacier; a well-developed end moraine shows that the ice front was there for some time. Krzyszkowski (2002) Sed. Geol. 149, 3–4 argues that end moraines often constitute alluvial fans, formed at the ice margin by the redeposition of supraglacial material. See Dyke and Lavelle (2000) Canadian J. Earth Scis 37 on major end moraines in Canada. Recessional moraines mark stages of stillstand during the retreat of the ice; a transverse moraine is a recessional if the up-glacier surface shows streamlining. Rogen moraines are fields of transverse moraines, 10–30 m in height, up to 1 km long, 100–300 m apart, and often linked by cross-ribs. Their origin is uncertain. De Geer moraines form where a glacier meets its proglacial lake, and consist of till, layered sand, and lake deposits (Evans et al. (2002) J. Quat. Sci. 17, 3). Push moraines occur when a glacier is retreating in the melt period but advancing in the cold season; see Krüger et al. (2002) Norwegian J. Geog. 56. Glaciohydraulic supercooling may aid the development of moraines created by melt-out from basal ice (Lawson et al. (1998) J. Glaciol. 44).
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