Ice Segregation as an Origin for Lenses of Non-Glacial Ice in “Ice-Cemented” Rock Glaciers

Abstract In order to flow with the gradients observed (10° to 15°) rock glaciers cannot be simply ice-cemented rock debris, but probably contain masses or lenses of debris-free ice. The nature and origin of the ice in rock glaciers that are in no way connected to ice glaciers has not been adequately...

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Bibliographic Details
Published in:Journal of Glaciology
Main Author: Wayne, William J.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1981
Subjects:
Ice
Online Access:http://dx.doi.org/10.1017/s0022143000011564
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000011564
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Summary:Abstract In order to flow with the gradients observed (10° to 15°) rock glaciers cannot be simply ice-cemented rock debris, but probably contain masses or lenses of debris-free ice. The nature and origin of the ice in rock glaciers that are in no way connected to ice glaciers has not been adequately explained. Rock glaciers and talus above them are permeable. Water from snow-melt and rain flows through the lower part of the debris on top of the bedrock floor. In the headward part of a rock glacier, where the total thickness is not great, if this groundwater flow is able to maintain water pressure against the base of an aggrading permafrost, segregation of ice lenses should take place. Ice segregation on a large scale would produce lenses of clear ice of sufficient size to permit the streams or lobes of rock debris to flow with gradients comparable to those of glaciers. It would also account for the substantial loss in volume that takes place when a rock glacier stabilizes and collapses.