Title | The deglacial to postglacial marine environments of SEBarrow Strait, Canadian Arctic Archipelago |
Publication Type | Journal Article |
Year of Publication | 2012 |
Authors | Pieńkowski, AJ, England, JH, Furze, MFA, Marret, F, Eynaud, F, Vilks, G, MacLean, B, Blasco, S, Scourse, JD |
Journal | Boreas |
Volume | 41 |
Issue | 2 |
Pagination | 141-179 |
ISSN | 1502-3885 |
Abstract | 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 ?18O and ?13C, 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. |
URL | http://dx.doi.org/10.1111/j.1502-3885.2011.00227.x |
DOI | 10.1111/j.1502-3885.2011.00227.x |