A REVIEW OF MULTI-PROXY DATA FOR THE YOUNGER DRYAS IN ATLANTIC CANADA

Citation
Fe. Mayle et Lc. Cwynar, A REVIEW OF MULTI-PROXY DATA FOR THE YOUNGER DRYAS IN ATLANTIC CANADA, Quaternary science reviews, 14(9), 1995, pp. 813-821
Citations number
37
Categorie Soggetti
Geosciences, Interdisciplinary",Geology
Journal title
ISSN journal
02773791
Volume
14
Issue
9
Year of publication
1995
Pages
813 - 821
Database
ISI
SICI code
0277-3791(1995)14:9<813:AROMDF>2.0.ZU;2-#
Abstract
Multi-proxy data obtained from lake sediments and buried organic seque nces is reviewed and discussed as evidence for the Younger Dryas cooli ng event in Atlantic Canada. Sedimentological studies indicate that la ke basins were subject to increased erosion due to climate cooling, wh ile glacial and periglacial sediments overlying peats have been attrib uted to the effects of small Younger Dryas ice-caps building up in hig hland areas of Nova Scotia. Pollen evidence from over 30 sites shows t wo broad patterns of Lateglacial vegetation change in the region. The Younger Dryas cooling caused the replacement of closed boreal forest b y shrub-tundra in southern New Brunswick and central mainland Nova Sco tia, and the replacement of shrub-tundra by herb-tundra in central New Brunswick, northern Nova Scotia and Newfoundland. Chironomid data ind icate that the Younger Dryas was marked by a drop in summer lake surfa ce-water temperatures of ca. 6 degrees C, while diatom data suggest th at marked limnological changes also occurred. Based on AMS C-14 dates from terrestrial plant macrofossils of 8 sites, the Younger Dryas even t in Atlantic Canada lasted from ca. 10,830 to 10,000 BP. These dates match most of those from northwest and central Europe, suggesting that this climatic event affected the entire North Atlantic region essenti ally simultaneously.