Late Cenozoic radiolarians of ODP Hole 175-1082A

Latest Miocene to Pleistocene poorly to well-preserved radiolarians were recovered from Hole 1082A in the Walvis Basin by Ocean Drilling Program Leg 175. Having moderate sedimentation rates and a good magnetostratigraphic record, this hole provides an excellent reference section for biochronology of the eastern South Atlantic Ocean. A set of radiolarian census data is given, and distinctive bioevents are identified and tied to the geomagnetic polarity time scale. This is the first attempt at a direct correlation of Neogene radiolarian bioevents with the geomagnetic polarity time scale in the South Atlantic off southwest Africa. Any one of the previously proposed zonal frameworks alone is hard to fully apply to radiolarian assemblages in Hole 1082A because of the rarity of the diagnostic species.