GEOSCAN Search Results: Fastlink


TitleLate-glacial (Allerød/Younger Dryas) buried organic deposits, Nova Scotia, Canada
AuthorMott, R J; Stea, R R
SourceQuaternary Science Reviews vol. 12, issue 8, 1993 p. 645-657,
Alt SeriesGeological Survey of Canada, Contribution Series 26292
PublisherElsevier BV
Mediapaper; on-line; digital
File formatpdf
ProvinceNova Scotia; New Brunswick; Quebec
NTS20O; 20P; 21A; 21B; 21G; 21H; 21I; 21J; 21O; 21P; 11C; 11D; 11E; 11F; 11L; 11K; 11M; 11N
AreaMagdalen Islands
Lat/Long WENS -68.0000 -60.0000 47.0000 43.0000
Subjectsorganic deposits; organic materials; wetlands; peat; climatic fluctuations; climate; deglaciation; glacial history; Wisconsinian glacial stage; mass wasting; solifluction; vegetation history; Allerod/Younger Dryas
Illustrationslocation maps; tables; schematic cross-sections; pollen diagrams
AbstractNumerous deposits of organic, shallow-pond sediments and wetland peat accumulations huffed by minerogenic sediments have been
discovered throughout Nova Scotia. They are interpreted as representing a late-glacial climatic oscillation correlative with the
Allerod/Younger Dryas event 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 reversion recorded in marly deposits began about 10.8 ka BP and continued or sustained cooling culminated in the burial of the organic deposits by minerogenic sediments indicative of solifluction and mass-wasting processes. Some deposits provide strong evidence for regeneration or rejuvenation of local glaciers. As the organic deposits are not as susceptible as lake sediments to contamination by old carbon, they provide a more reliable chronological framework for deglaciation and late-glacial vegetational history. Palynological evidence shows that pioneer herb tundra communities colonized some areas shortly after 13 ka BP. Willow and birch shrubs followed soon after. Spruce woodlands had migrated into the region prior to 10.8 ka BP but had not yet reached the northeast 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 the buffed 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.