Genesis of marginal moraines in the Caucasus |
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| Authors: | LEONID R SEREBRYANNY REI V ORLOV |
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| Institution: | Institute of Geography, USSR Academy of Sciences, Staromonetnyi 29, 109017 Moscow, USSR |
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| Abstract: | Composition and fabric of different moraines in the glaciated areas of Central Caucasus were studied to elucidate sedimentary environments and geomorphological processes. Methods used included particle-size distribution, pebble and mineral counts, shape analysis of pebbles, and till fabric analysis. Samples were taken from superglacial and basal debris, marginal moraine ridges and till horizons, and quantitative parameters were established for different glacial environments and till accumulation processes. Considerable differences in composition and fabric of superglacial and basal debris were caused by their specific transport conditions. Most marginal moraines consist of material similar to basal debris and only the topmost parts of some ridges have a noticeable incorporation of superglacial debris. These results point to considerable erosion of mountain valleys by temperate glaciers. Previous geomorphological investigations have emphasized the importance of superglacial debris in the formation of marginal moraines by alpine glaciers, but this viewpoint is not supported by the studies performed. |
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