Foliation Pattern of Gulkana Glacier, Alaska Range, Alaska

Abstract Gulkana Glacier, consisting of three major ice streams and two prominent ice falls, displays a complex foliation pattern. In the western ice stream, below Gabriel Ice Fall, the foliation is transverse, developing gradually down-glacier into a distinct series of nested arcs. The arcs are con...

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Bibliographic Details
Published in:Journal of Glaciology
Main Author: Rutter, Nathaniel W.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1965
Subjects:
Online Access:http://dx.doi.org/10.1017/s0022143000018700
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000018700
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Summary:Abstract Gulkana Glacier, consisting of three major ice streams and two prominent ice falls, displays a complex foliation pattern. In the western ice stream, below Gabriel Ice Fall, the foliation is transverse, developing gradually down-glacier into a distinct series of nested arcs. The arcs are concave up-glacier with the foliation dipping steeply toward the inside of the arc. A similar pattern is displayed in the eastern ice stream but there the pattern is less distinct with the arcs evolving into a series of nested semi-arcs. The central ice stream is characterized by vertical layers of foliation with a longitudinal strike. Apparently, longitudinal foliation will form in areas with strong compression and shear caused by differential flow velocity such as where two ice streams unite. The foliation that ultimately displays arcuate (or semi-arcuate) patterns originates principally at the base of an ice fall where strong longitudinal compression is present due to the decrease of gradient.