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.