THE USE OF PALYNOMORPHS AS A PROXY FOR RECONSTRUCTING THE PALEOCEANOGRAPHIC CHANGES IN THE MIDDLE CAPE BASIN (ODP LEG 175)

Studies of Quaternary and Recent dinoflagellate cyst assemblages have shown that distinct trends in sediments are controlled by such environmental factors as sea surface temperature, salinity, coastal ocean signals and productivity. Thus, they are good proxies for reconstructing paleoclimatologic and paleoceanographic conditions in the Middle Cape Basin (ODP Leg 175) which is one of the great upwelling systems in the world because of the effects of the Benguela current. The sediments are primarily calcareous oozes that surprising have diverse assemblages of dinoflagellate cysts and few spores and pollen. A preliminary low-resolution palynologic study of 19 samples from Hole 1085A yielded potentially useful data on paleoceanographic and paleoclimatic conditions during the middle Miocene-late Pliocene. The results correlated well with those generated by other researchers whose techniques included micropaleontology, inorganic geochemistry, and organic geochemistry.The objectives of the preliminary study are being met by a high-resolution sampling of more sediments from Holes 1085A, 1086A, and 1087C in the current study with a view to using palynomorphs and palynofacies to document paleoceanographic changes and marine/nonmarine paleoclimatic signals recorded by the sediments.