LAND-SEA CORRELATION BY MEANS OF TERRESTRIAL AND MARINE PALYNOMORPHS FROM THE EQUATORIAL EAST ATLANTIC - PHASING OF SE TRADE WINDS AND THE OCEANIC PRODUCTIVITY

Sporomorphs and dinoflagellate cysts from site GIK16867 in the norther n Angola Basin record the vegetation history of the West African fores t during the last 700 ka in relation to changes in salinity and produc tivity of the eastern Gulf of Guinea. During most cool and cold period s, the Afromontane forest, rather than the open grass-rich dry forest, expanded to lower altitudes partly replacing the lowland rain forest of the borderlands east of the Gulf of Guinea. Except in Stage 3, when oceanic productivity was high during a period of decreased atmospheri c circulation, high oceanic productivity is correlated to strong winds . The response of marine productivity in the course of a climatic cycl e, however, is earlier than that of wind vigour and makes wind-stress- induced oceanic upwelling in the area less likely. Monsoon variation i s well illustrated by the pollen record of increased lowland rain fore st that is paired to the dinoflagellate cyst record of decreased salin ity forced by increased precipitation and run-off. (C) 1998 Elsevier S cience B.V. All rights reserved.