Modern and palaeo-oceanographic 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 (B1–B6): • mib cell (temperature, salinity, dissolved oxygen, total organic matter: 10.3°C, 34.94‰, 1.2 ml/l, 6.2%): Palmoconcha walvisbaiensis, Cytherella namibensis, Garciaella knysnaensis robusta and Neocaudites lordi. x02022; lvis cell (11.0°C, 35.00‰, 1.0 ml/l, 9.2%): Palmoconcha walvisbaiensis, Cytherella namibensis, Garciaella knysnaensis robusta, Buntonia rogersi, Neocaudites lordi and Ruggieria cytheropteroides (leeward side only). x02022; deritz cell (9.1°C, 34.77‰, 1.8 ml/l, 6.3%): Palmoconcha walvisbaiensis, Cytherella namibensis, Incongruellina venusta, Kuiperiana angulata, and Ruggieria cytheropteroides (leeward side only). x02022; maqua cell (10.0°C, 34.82‰, 2.4 ml/l, 3.1%): Pseudokeijella lepralioides and Ruggieria cytheropteroides. x02022; lumbine cell (8.3°C, 34.70‰, 3.1 ml/l, 3.9%): Ruggieria cytheropteroides, Pseudokeijella lepralioides, Poseidonamicus panopsus and Ambostracon (A.) flabellicostata. x02022; ninsula cell (8.9°C, 34.63‰, 3.6 ml/l, 1.9%): Pseudokeijella lepralioides, Ambostracon (A.) keeleri, Cytherella dromedaria, Neocytherideis boomeri, Xestoleberis africana, Neocaudites osseus, Coquimba birchi and Urocythereis arcana. ocene palaeo-upwelling characteristics of the shelf north-west of Luderitz are investigated by analysing the ostracod faunas, sediment textures and mineralogy of three large-volume gravity cores. Q-mode factor analyses using previously published transfer functions allow predictions for benthic environmental parameters. During the Late Pleistocene the area experienced less-intense upwelling and lower primary productivity than at present, in an environment equated with a modified Peninsula cell (B6): B7 cell (9.6°C, 34.73‰, 3.2 ml/l, 3.9%), Neocaudites lordi, Ambostracon (A.) keeleri, Bairdoppilata simplex, Paracypris lacrimata, Parakrithella simpsoni, Xestoleberis hartmanni, Ruggieria cytheropteroides and Pseudokeijella lepralioides. In Middle and Early Pleistocene/Late Pliocene times, the core sites lay closer inshore, adjacent to evaporite (halite) and authigenic (phosphorite)-rich lagoons, with a high-intensity upwelling Walvis-like cell (B1) to the north-west, and a low-intensity upwelling cell (B7) to the south.