Météorisation des Blocs de Granite à la Surface des Pédiments dans le Nord du Yukon, Canada

Abstract This article describes how tors calve granite boulders which are then distributed in three zones on the surrounding pediments. The boulders are broken down to granules, sand, silt and clay on the surface of the pediments. The study site is located on a rounded hill of the Old Crow batholith...

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Bibliographic Details
Published in:Permafrost and Periglacial Processes
Main Authors: Bjornson, Jean, Lauriol, Bernard
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2001
Subjects:
Online Access:http://dx.doi.org/10.1002/ppp.391
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fppp.391
https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.391
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Summary:Abstract This article describes how tors calve granite boulders which are then distributed in three zones on the surrounding pediments. The boulders are broken down to granules, sand, silt and clay on the surface of the pediments. The study site is located on a rounded hill of the Old Crow batholith near the Yukon‐Alaska border. The methods and techniques used were grain size analysis, rock and sediment geochemistry and boulder fabric. Results show that boulders become smaller and less frequent on the pediment as distance from the tor increases. Weathering processes disaggregate the boulders before they reach the talwegs. Chronological evaluation suggests that 10s to 100s ka are necessary for weathering to reduce the boulders to fine particles. Copyright © 2001 John Wiley & Sons, Ltd.