Evidence for coalescence of Laurentide and Rocky Mountain glaciers east of Glacier National Park, Montana

Auteur :
KARLSTROM, E.T.

Description :
Evidence indicates that Laurentide and Rocky Mountain piedmont glaciers coalesced in the Willow Creek drainage east of Glacier National Park. Based on relative soil development, alpine tills in the North Fork of the Milk River could be two ages (late Wisconsin and earlier Wisconsin or late Illinoian?), suggesting two distinct coalescence events. However, identifying provenance of surficial deposits can be problematic owing to the repeated mixing of sediments, which undoubtedly occurred in unstable proglacial environments. In particular, granite erratics, probably ice-rafted, commonly mantle landforms not constructed by the Laurentide glacier(s).


Type de document :
Article de périodique

Source :
Physical geography, issn : 0272-3646, 1999, vol. 20, n°. 3, p. 225-239, Collation : Illustration, Références bibliographiques : 35 ref.

Date :
1999

Editeur :
Pays édition : Royaume-Uni, Abingdon, Taylor and Francis