The deglacial to postglacial marine environments of SE Barrow Strait, Canadian Arctic Archipelago

Author
Pienkowski, Anna J.
England, John H.
Furze, Mark F.A.
Marret, Fabienne
Eynaud, Frederique
Vilks, Gustav
MacLean, Brian
Blasco, Steve
Scourse, James D.
Faculty Advisor
Date
2012
Keywords
Microfossils , Sediments , Sedimentation & deposition , Climate change , Holocene Epoch , Glaciation , Pleistocene paleoclimatology , Arctic Archipelago (Nunavut & N.W.T.) , Nunavut , Northwest Territories
Abstract (summary)
Core 86027-144 (74°15.56′N, 91°14.21′W) represents a rare, continuous record of Late Pleistocene to Holocene sediments from High Arctic Canada extending from the end of the Last Glaciation. Based on microfossils (dinocysts, non-pollen palynomorphs, benthic and planktonic foraminifera), foraminiferal δ18O and δ13C, and sedimentology, seven palaeoenvironmental zones were identified. Zone I (>10.8 cal. ka BP) records deglaciation, ice-sheet destabilization, float-off and subsequent break-up. Zone II (c. 10.8–10.4 cal. ka BP) shows ice-proximal to ice-distal glaciomarine conditions, interrupted by pervasive land-fast sea-ice marked by a hiatus in coarse sediment deposition. Significant biological activity starts in Zone III (10.4–9.9 cal. ka BP), where planktonic foraminifera (Neogloboquadrina pachyderma) suggest early oceanic throughflow. Surface waters flowed NW–SE; however, the deep-water origin remains unclear (potentially NW Arctic Ocean or Baffin Bay). Postglacial amelioration (open-water season greater than present) in Zone IV (9.9–7.8 cal. ka BP) perhaps corresponds to the regional ‘Holocene Thermal Maximum’ previously proposed. A transitional period (Zone V; 7.8–6.7 cal. ka BP) of rapid environmental change fluctuating on a scale not observed today is marked by increasing sea-ice and reduced oceanic influence. This probably signals the exclusion of deeper Atlantic water owing to the glacio-isostatic shallowing of inter-island sills, coupled with generally cooling climate. Conditions analogous to those at present, with increased sea-ice and modern microfossil assemblages, commence at c. 6.7 cal. ka BP (zones VI–VII). Although climate ultimately forces long-term environmental trends, core 86027-144 data imply that regional dynamics, especially changes in sea-level, exert a significant control on marine conditions throughout the Canadian Arctic Archipelago.
Publication Information
Pieńkowski, A. J., England, J. H., Furze, M. F. A., Marret, F., Eynaud, F., Vilks, G., MacLean, B., Blasco, S. & Scourse, J. D. (2011): The deglacial to postglacial marine environments of SE Barrow Strait, Canadian Arctic Archipelago. Boreas, 10.1111/j.1502-3885.2011.00227.x. ISSN 0300-9483.
DOI
Notes
Item Type
Article
Language
English
Rights
All Rights Reserved