Age determination and faunal composition of sediments off northern Greenland

• Main Authors: Nørgaard-Pedersen, Niels, Mikkelsen, Naja, Lassen, Susanne Juul, Kristoffersen, Yngve, Sheldon, Emma
• Format: Dataset
• Language: English
• Published: PANGAEA 2014
• Subjects: Arctic; Arctic Ocean; Canada; Greenland; Foraminifera*; Lomonosov Ridge; Sea ice
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.833626; https://doi.org/10.1594/PANGAEA.833626

We present a record encompassing marine isotope stages 7-1 from a hitherto unexplored and heavily ice-covered area of the Arctic Ocean, the Lomonosov Ridge off the northern Greenland-Canada continental margin, using nannofossil and benthic foraminifera stratigraphy. Planktic foraminifera assemblages are used as a key paleoceanographic proxy, and a surprisingly large variability is found for an interior Arctic Ocean site. Abundant small (63-125 µm) subpolar Turborotalita quinqueloba occur in two sections, possibly representing substages 5e (last interglacial) and 5a (warm interstadial). However, the present-day circulation pattern and the very distant location of high productive regions cannot explain such high abundances of subpolar specimens in the interior, perennially sea ice-covered Arctic Ocean. Hence our proxy record indicates that last interglacial sea ice concentrations were reduced off some areas of northern Greenland-Canada. Whether this was part of a larger regional pattern or it represents the influence of polynya areas with locally increased productivity remains to be solved. With respect to glacial conditions, increased ice-rafted debris (IRD) deposition in the area appears to be associated with glacial stages 6, 4, and late 3. Stage 2 sediments (including the Last Glacial Maximum) are condensed with a sparse IRD content only.