Glacial sediment-landform associations and palaeoclimate during the last glaciation, Strait of Magellan, Chile

Glacial sediments and landforms preserved beside the Strait of Magellan record repeated advances of an outlet of the Patagonian Icefield during and following the last glacial maximum (LGM; similar to 25,000-14,000 C-14 yr B.P,). Ice-marginal landform assemblages consist of thrust moraine complexes,...

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Bibliographic Details
Published in:Quaternary Research
Main Authors: Benn, Douglas Iain, Clapperton, CM
Format: Article in Journal/Newspaper
Language:English
Published: 2000
Subjects:
South America
Chile
paleoclimate
glacier reconstruction
last glacial maximum
LATE PLEISTOCENE
ARCTIC CANADA
ICE SHELF
PATAGONIA
CLIMATE
POLLEN
BEETLE
DEFORMATION
VEGETATION
EXAMPLES
Arctic
Canada
Lever
Patagonia
glacier*
Ice
Ice Shelf
permafrost
Online Access:https://research-portal.st-andrews.ac.uk/en/researchoutput/glacial-sedimentlandform-associations-and-palaeoclimate-during-the-last-glaciation-strait-of-magellan-chile(b7d2f461-710e-49d0-94b7-c3e55ac38c8d).html
https://doi.org/10.1006/qres.2000.2140
http://www.scopus.com/inward/record.url?scp=0033885751&partnerID=8YFLogxK
Description
Summary:Glacial sediments and landforms preserved beside the Strait of Magellan record repeated advances of an outlet of the Patagonian Icefield during and following the last glacial maximum (LGM; similar to 25,000-14,000 C-14 yr B.P,). Ice-marginal landform assemblages consist of thrust moraine complexes, kame and kettle topography, and lateral meltwater channels, very similar to those found at the margins of modern subpolar glaciers. Taken together with other forms of paleoenvironmental evidence, the landform assemblages show that, during the LGM and late-glacial time, permafrost occurred near sea lever in southernmost South America. This finding implies that mean annual temperatures were similar to 7-8 degrees C lower than at present, somewhat lower than those reconstructed by current glacier-climatic models. Comparison,vith precipitation-temperature relationships for modern glaciers suggests, in addition, that precipitation levels were lower than today. Reduced glacial-age precipitation may have resulted from a precipitation shadow induced by the Patagonian Icefield, an equatorward migration of the average position of westerly cyclonic storm tracks in the southern midlatitudes, or both these factors. (C) 2000 University of Washington.

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