Late Quaternary stratigraphy and palaeoceanographic change in the northern Rockall Trough, North Atlantic Ocean

Abstract

Abstract A series of six shallow gravity cores, taken from a variety of sedimentary settings in the northern Rockall Trough, have been analysed using microfossil and sedimentological techniques. Cores from sediment waves on the Barra Fan are interpreted as being sequences of hemipelagites, turbidites and hemiturbidites. Northeastern Rockall Trough cores, from slope apron, escarpment and sediment drift areas are interpreted as hemipelagites, with glaciomarine deposits interbedded with and overlain by muddy-silty and sandy contourites. The dinoflagellate cyst, planktonic foraminifera and nannofossil biostratigraphy reveals a four-fold deglaciation record, with a single long core from the Barra Fan seemingly containing all four divisions of the Late Glacial, Allerød-Bölling, Younger Dryas and Holocene intervals. The sedimentary record suggests that deglaciation in the North Atlantic Ocean was not a simple linear process but an irregular, non-linear series of rapid events characterized by sudden sea-surface temperature changes, and fluctuating bottom-current activity.