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TitreEolian activity in relation to late glacial and early Holocene environmental conditions, southwestern Yukon and western arctic, North America
AuteurWolfe, S A; Bond, J; Lamothe, M
SourcePrairie Summit, joint conference of Canadian Association of Geographers, Canadian Cartographic Association, Canadian Geomorphology Research Group, Canadian Remote Sensing Society, program and abstracts/Le sommet des Prairies, Conférence conjointe de l'Association canadienne des géographes, l'Association canadienne de cartographie, le Groupe canadien de recherche en géomorphologie, la Société canadienne de télédétection, programme et résumés; 2010 p. 223
Séries alt.Secteur des sciences de la Terre, Contribution externe 20090455
RéunionPrairie Summit, CAG-CRSS-CGRG AGM; Regina; CA; juin 1-5, 2010
SNRC105D; 105E; 105M
Régionsouthwestern Yukon
Lat/Long OENS-136.0000 -134.0000 62.0000 60.0000
Sujetsdépôts éoliens; loess; dunes; transport des sediments; Holocène; sédimentologie; Nature et environnement; Cénozoïque
ProgrammeGéosciences de changements climatiques, Études paléo-environnementales sur les changements climatiques
Résumé(disponible en anglais seulement)
Eolian deposits of the Yukon consist of loess mantles, stabilized and semi-active dune fields, stabilized sand sheets, active lakeshore and riverside dunes, and some cliff-top eolian deposits. Optical dating in central and southern Yukon reveal that dune fields in river valley settings stabilized as late as 9 to 8.5 ka, well after the retreat of Cordilleran glaciers. Eolian deposition in western arctic North America, including arctic coastal lowland dune fields, cliff-top eolian deposits and loess, show similar responses of activity during the late glacial period into the Holocene Thermal Maximum, with reduced activity after 9 to 8 ka. Continued post-glacial eolian activity throughout the region was most likely related to warm, dry conditions during the Holocene Thermal Maximum caused by peak summer insolation. Early Holocene dune stabilization in river-valley settings was probably due to cooler, moister conditions, and replacement of shrub and forest tundra vegetation by boreal forest cover dominated by spruce; conditions that, in contrast, were conducive to enhanced loess accumulation in southeastern Alaska. In central Yukon, a reduced loess accumulation in the early Holocene may reflect a change in river hydrology from glacial meltwater flow dominated to a predominantly nival flow regime.