Bottom sediments of the largest lake of the East African Rift system, Lake Tanganyika (length 650 km; maximum depth 1470 m; volume 18,800 km³) (Fig. 1), were extensively studied between 1983 and 1986 by Project PROBE of Duke University (U.S.A.) and Project GEORIFT (1984-1985) of Elf Aquitaine (France), using a wide range of methods such as reflection seismology, piston coring, and dredging. Interpretation of multifold reflection seismic profiles collected by Project PROBE suggests up to 4 km of sediment has accumulated within local depocenters. In addition, seismic profiles exhibit several seismic discontinuities and associated sequences, interpreted to have resulted from large-scale, temporal changes in local tectonics and/or climate (Burgess and others, 1988; Scholz and Rosendahl, 1988).

Our interpretation of Recent and Modern profundal sediments in Lake Tanganyika is based on high-resolution, 5-kHz seismic surveys, along with multiple Kullenberg cores from the north and south basins of the lake collected during the GEORIFT project, and our interpretation of littoral clastic and biogenic sedimentation is based on grab sampling, observations from SCUBA, and gravity cores collected by the University of Arizona (Cohen, 1990; Soreghan and Cohen, 1991). These previous studies were supplemented by gravity cores collected in the Burundian part of the northern basin during a 1992 joint field operation by the University of Arizona (U.S.A.), the INSU-CNRS (France), and the CASIMIR project (Belgium). In this paper, our goal is to illustrate fundamental differences in facies associations within Lake Tanganyika that are, to a large degree, controlled by the basin structure.