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 adequatel...
| Main Author: | |
|---|---|
| Format: | Text |
| Language: | unknown |
| Published: |
DigitalCommons@University of Nebraska - Lincoln
1981
|
| Subjects: | |
| Online Access: | https://digitalcommons.unl.edu/geosciencefacpub/564 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1574/viewcontent/Wayne_JG_1983_Ice_segregation.pdf |
| 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. RESUME. La segregation de la glace a l'origine des lentilles de glace d'origine non glaciaire dans les glaciers rocheux soudes par la glace. Pour qu'ils puissent s'ecouler sur les pentes OU on les observe (10° a 15°), les glaciers rocheux ne peuvent pas etre simplement constitues de debris rocheux soudes par la glace, mais contient probablement des blocs ou des lentilles de glace depourvus de sediments. La nature et l'origine de la glace dans les glaciers rocheux, qui ne sont en aucune maniere relies a des glaciers de glace, n'a pas ete correctement expliquee. Les glaciers rocheux et les talus qui les surplombent sont permeables. Les eaux de fusion et de pluie coulent a travers la partie inferieure des blocs sur Ie bedrock. Dans la partie haute d'un glacier rocheux, lorsque l'epaisseur totale n'est pas grande, si l'ecoulement sur Ie bedrock est suffisant pour maintenir la pression hydrostatique contre la base d'un permafrost en contrepente, il peut y avoir segregation de lentilles de glace. La segregation de la glace sur une ... |
|---|