METEOR expedition M34 was carried out as part of the long-range investigations being pursued under the Special Research Project (SFB) No. 261, for the reconstruction of mass budget and current systems in the South Atlantic during the Late Quaternary. On METEOR cruise M34 samples and data were recovered from the upwelling region off Namibia, the central South Atlantic, and off North Brazil and Barbados. The cruise consisted of four legs, starting in Cape Town on January 3, 1996, and ending at Barbados on April 15, 1996. During the first leg, seismic and echographic measurements along a series of profiles as well as the sampling of surface sediments in the Cape Basin area was performed. These investigations provide basic information for a deep coring operation by the international Ocean Drilling Program, which is being prepared for by the University of Bremen. The main objective of the second leg was to investigate the biogeochemical processes in sediments of the upwelling area off Namibia. The scientific groups of the Max-Planck-Institut for Marine Microbiology and the Department of Geoscience of the University of Bremen worked closely together to produce new data for the biogeochemical reaction rates. On the third leg sediment cores were receovered to supplement the sample materials of SFB 261 in the central South Atlantic. Core-station profiles were taken from the Angola Basin to the Mid-Ocean-Ridge, and from there into the Brazil Basin. This cruise served also as a continuation of the investigations of the Institut für Meereskunde Kiel and the Traceroceanography of the University of Bremen, which are studying the spread of bottom water on the southern edge of the Brazil Basin, and determining temporal changes in the chlorofluoromethane content of the water, respectively. Three signal generator moorings were also recovered. The main objective of the fourth leg was to determine the seasonal particle sedimentaton in the western equatorial Atlantic and to extend the investigations of sediments from the Amazon Fan and Ceara Rise.