Late quaternary calcareous nannofossil biozonation, chronology and palaeo-oceanography in areas north of the faeroe-iceland ridge

Abstract

The stratigraphic distribution of late Quaternary calcareous nannofossils from the European Arctic Ocean, the Fram Strait and the Norwegian and Greenland seas are summarised in a biozonation scheme. The nannofossil events are directly correlated to oxygen isotope stratigraphy, leading to an absolute chronology comprising approximately the last 500 ka. The zones are defined by the qualitative and quantitative content of calcareous nannofossils. Zones N-G 2, 4, 6, 8 and 10 comprise intervals mainly barren of nannofossils. Zone N-G 1 is characterised by high abundances of Coccolithus pelagicus and Emiliania huxleyi, Zone N-G 3 is recognised by dominant Gephyrocapsa muellerae and common E. huxleyi. Zone N-G 5 is characterised by dominant G. aperta, N-G 7 by dominant G. muellerae, N-G 9 by common G. muellerae, G. aperta and G. caribbeanica and Zone N-G 11 is recognised by dominant G. caribbeanica and rare Pseudoemiliania lacunosa. Intervals in which nannofossils occur in high abundances reflect comparatively warmer periods and influences of North Atlantic surface water. Strong inflows of North Atlantic water have occurred several times during the last 500 ka; in oxygen isotope stage 1 (the last 8 ka) and in oxygen isotope stages 5, 11, 12 and 13, North Atlantic surface water penetrated into the central parts of the Norwegian and Greenland seas also during oxygen isotope stage 9. Nannofossil barren intervals are mainly formed during time periods with a year-round ice-cover.