MIDDLE PLEISTOCENE POLLEN BIOSTRATIGRAPHY IN THE CENTRAL NORTH-SEA

Middle Pleistocene sequences from the northernmost (Fladen Ground) and the southernmost (Devil's Hole area) parts of the British sector of t he central North Sea are correlated on the basis of pollen biostratigr aphy. Four pollen stratigraphies are compared, with reference taken to existing borehole and seismic data. The most pronounced influence of reworked pre-Quaternary sediments are present in an upper interval, ri ch in pre-Neogene palynomorphs, and in a lower interval, rich in Neoge ne palynomorphs. This change can be related to Middle Pleistocene glac ial periods. The pollen content in the younger interval indicates a Br itish provenance, possibly correlated with the Saalian stage. The poll en content in the older interval indicates derivation from the Scandin avian ice sheet, and may correlate with the Elsterian stage. The polle n stratigraphies between these two intervals reflect a vegetational tr ansition from dwarf shrub heaths and peatlands towards boreal forests, possibly followed by a return to a more open landscape. This pollen s tratigraphical succession is best preserved in the Devil's Hole sequen ces. In the Fladen Ground the upper part of the sequence may have been glacially eroded. Deposits of Cromerian Complex age occur at base of the Middle Pleistocene sequences. (C) 1998 Elsevier Science Ltd. All r ights reserved.