Numerous deposits of organic, shallow-pond sediments and wetland peat
accumulations buried by minerogenic sediments have been discovered thr
oughout Nova Scotia. They are interpreted as representing a late-glaci
al climatic oscillation correlative with the Allerod/Younger Dryas eve
nt of Europe and the North Atlantic Ocean. The organic deposits began
forming during the warm or warming interval following deglaciation and
often record a transition to colder conditions. The climatic reversio
n recorded in many deposits began about 10.8 ka BP and continued or su
stained cooling culminated in the burial of the organic deposits by mi
nerogenic sediments indicative of solifluction and mass-wasting proces
ses. Some deposits provide strong evidence for regeneration, or rejuve
nation of local glaciers. As the organic deposits are not as susceptib
le as lake sediments to contamination by old carbon, they provide a mo
re reliable chronological framework for deglaciation and late-glacial
vegetational history. Palynological evidence shows that pioneer herb t
undra communities colonized some areas shortly after 13 ka BP. Willow
and birch shrubs followed soon after. Spruce woodlands had migrated in
to the region prior to 10.8 ka BP but had not yet reached the northeas
t mainland and Cape Breton Island. Cooling after 10.8 ka BP decimated
tree populations and favoured a return to shrub and herb communities.
The record in die buried deposits was then truncated by deposition of
minerogenic sediments, and lake sediment sequences from deeper basins
with continuous sedimentation are required to complete the record.