Lateral plucking as a mechanism for elongate erosional glacial bedforms : explaining megagrooves in Britain and Canada

Auteur(s) et Affiliation(s)



Description :
Here the AA. report 2 previously undocumented megagroove fields from Ungava, Canada, and northern England, and present new analyses of the megagrooves from NW Scotland. This paper seeks to determine the nature of the lithological and structural controls on the occurrence and formation of megagrooves. Detailed analysis of megagrooves in NW Scotland shows that neither glacio-fluvial erosion, nor differential abrasion was the dominant mechanism of formation. A mechanism, here termed ‘lateral plucking’, is suggested that involves block plucking on rock steps parallel to ice flow. Megagrooves are potentially useful as palaeo-ice flow indicators in areas devoid of till, and can thus complement the palaeo-ice stream datasets which are presently largely based on soft-sediment landform studies.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2011, vol. 36, n°. 10, p. 1335-1349, nombre de pages : 15, Références bibliographiques : 2 p.

Date :
2011

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley