The Benguela Current is a northward-flowing cool current of the South Atlantic (Fig. F1). It is largely driven by the southeast trade winds and associated with strong coastal upwelling along the continental margin of Namibia, Africa. Ocean Drilling Program (ODP) Leg 175 was conducted to reconstruct the paleoceanography of the Angola-Benguela Current system and the paleoclimates of its nearby African continent (Wefer, Berger, Richter, et al., 1998). During this cruise, Site 1082 was drilled on the continental slope in the Walvis Bay area because it plays a large role in the reconstruction of the history of the Benguela Current as well as the history of the related upwelling. This paper is designed to present census data of the radiolarian assemblages from Hole 1082A, which are expected to record changes and timing of the ocean climate, structures, and productivity over the last 6 m.y. in the region of the Benguela Current off Namibia. Detailed radiolarian faunal analyses and paleoceanographic interpretations will appear elsewhere.
Neogene radiolarian stratigraphy for the South Atlantic off southwest Africa was first published by Pisias and Moore (1978) on the basis of the material collected on Deep Sea Drilling Project (DSDP) Leg 40, but no absolute age estimates have been attempted. DSDP Leg 75 was later conducted to the neighboring area, but no radiolarian report was proposed for it. Of the 13 sites drilled by ODP Leg 175, Site 1082 seems to be the most hopeful site for estimation of absolute ages of radiolarian events because this site produces a record of magnetic polarity reversals that covers the longest time interval down to the latest Miocene. Some of the other sites (Sites 1075-1081, 1083, and 1084) cover the reversal records of shorter time intervals, and in the rest of the Sites (1085, 1086, and 1087,) most of the stratigraphic section below the upper Pliocene does not contain any radiolarians (Wefer, Berger, Richter, et al., 1998). The present study provides correlation between the radiolarian stratigraphy of Hole 1082A and the geomagnetic time scale. Some biostratigraphic comments are also mentioned below.