MODERN AND PALEOCEANOGRAPHIC ENVIRONMENTS UNDER BENGUELA UPWELLING CELLS OFF SOUTHERN NAMIBIA

Averaged benthic physical and chemical, and key microfaunal (Ostracoda ) parameters of the bottom waters and substrate allow a ranking of the intensity of upwelling in the modern cells off southwestern Africa (B 1-B6): B1 Namib cell (temperature, salinity, dissolved oxygen, total o rganic matter: 10.3 degrees C, 34.94 parts per thousand, 1.2 ml/l, 6.2 %): Palmoconcha walvisbaiensis, Cytherella namibensis, Garciaella knys naensis robusta and Neocaudites lordi. B2 Walvis cell (11.0 degrees C, 35.00 parts per thousand, 1.0 ml/l, 9.2%): Palmoconcha walvisbaiensis , Cytherella namibensis, Garciaella knysnaensis robusta, Buntonia roge rsi, Neocaudites lordi and Ruggieria cytheropteroides (leeward side on ly). B3 Luderitz cell (9.1 degrees C, 34.77 parts per thousand, 1.8 ml /l, 6.3%): Palmoconcha walvisbaiensis, Cytherella namibensis, Incongru ellina venusta, Kuiperiana angulata, and Ruggieria cytheropteroides (l eeward side only). B4 Namaqua cell (10.0 degrees C, 34.82 parts per th ousand, 2.4 ml/l, 3.1%): Pseudokeijella lepralioides and Ruggieria cyt heropteroides. B5 Columbine cell (8.3 degrees C, 34.70 parts per thous and, 3.1 ml/l, 3.9%): Ruggieria cytheropteroides, Pseudokeijella lepra lioides, Poseidonamicus panopsus and Ambostracon (A.) flabellicostata. B6 Peninsula cell (8.9 degrees C, 34.63 parts per thousand, 3.6 ml/l, 1.9%): Pseudokeijella lepralioides, Ambostracon (A.) keeleri, Cythere lla dromedaria, Neocytherideis boomeri, Xestoleberis africana, Neocaud ites osseus, Coquimba birchi and Urocythereis arcana. Pleistocene pala eo-upwelling characteristics of the shelf north-west of Luderitz are i nvestigated by analysing the ostracod faunas, sediment textures and mi neralogy of three large-volume gravity cores. Q-mode factor analyses u sing previously published transfer functions allow predictions for ben thic environmental parameters. During the Late Pleistocene the area ex perienced less-intense upwelling and lower primary productivity than a t present, in an environment equated with a modified Peninsula cell (B 6): B7 cell (9.6 degrees C, 34.73 parts per thousand, 3.2 ml/l, 3.9%), Neocaunites lordi, Ambostracon (A.) keeleri, Bairdoppilata simplex, P aracypris lacrimata, Parakrithella simpsoni, Xestoleberis hartmanni, R uggieria cytheropteroides and Pseudokeijella lepralioides. In Middle a nd Early Pleistocene/Late Pliocene times, the core sites lay closer in shore, adjacent to evaporite (halite) and authigenic (phosphorite)-ric h lagoons, with a high-intensity upwelling Walvis-like cell (B1) to th e north-west, and a low-intensity upwelling cell (B7) to the south.