LATE PLEISTOCENE FORAMINIFERAL ANALYSIS OF ODP SITE 1085, SOUTHWEST AFRICAN CONTINENTAL MARGIN

Despite its importance as the time in which hominids evolved, there is uncertainty about the climate in southern Africa in the Plio-Pleistocene. The purpose of this study is to add to what is known about the conditions of southern Africa during the late Pleistocene (200 ka to 0). To this end, we are determining changes in upwelling productivity associated with changes in winds.

 

Measuring the occurrence of planktonic foraminifera from the site will give an approximate measure of the amount of upwelling in the area. Giraudeau (1993) identified three major foraminiferal assemblages on the southwestern African continental margin. The first assemblage, typified by polar taxa such as Neogloboquadrina pachyderma and Globigerina quinqueloba, is found in regions subject to upwelling. The second, typified, by Globorotalia inflata and G. truncatulinoides, is the offshore oligotrophic environment. The third, typified by Globigerina bulloides and Neogloboquadrina pachyderma (right-coiling), is the productive intermediate zone between the upwelled and oligotrophic waters. Preliminary data indicates that the third assemblage may be the most common at the site.