Late Quaternary planktic foraminifera assemblages in the South Atlantic Ocean: quantitative determination and preservational aspects.

Abstract

In order to determine a calibration of the modern to the fossil situation in the South Atlantic Ocean four surface sediment depth-transects into the Brazil-, the Guinea-, the western and the eastern Cape Basin were investigated. Late Quaternary paleoceanographic and paleoclimatic aspects were focussed on the central equatorial Atlantic and the time frame of 300 kyrs.The modern South Atlantic situation. In surface sediments of the central equatorial Atlantic the planktic foraminiferal assemblages are dominated by tropical (G. sacculifer) and subtropical (G. ruber) index species. In the northern Cape Basin (Walvis Ridge) transitional species (G. inflata ) are of major importance. At the Namibia Continental Margin species showing also a certain preference to nutrient enriched water masses are abundant (G. bulloides, N. pachyderma ). Sea surface temperatures (SST's) estimated by factor analysis reveal excellent correspondence to the data measured by Levitus and Boyer (1994).