Sites 1082 (1290 m) and 1083 (2200 m), together with DSDP Sites 532 and 362 (1331 and 1325 m water depth, respectively) and Site 1081 (760 m water depth), form a transect that is central to the reconstruction of the history of the Benguela Current. Details on the background and objectives for this entire set of sites, including Site 1082, are given in the "Site 1081" chapter (this volume). This site is closest to the coast and is expected to contain a direct record of upwelling history in the Walvis Bay area. The DSDP sites are farther seaward of the upwelling center but contain an upwelling signal that was transported to this location by the Benguela Current and its filaments and eddies. Site 1082 has a similar water depth to that of DSDP Site 532 but lies about 120 km to the southeast, within the Northern Cape Basin.
Compared with DSDP Site 532, which shows evidence of sediment redeposition (seen as mud waves in seismic profiles), Site 1082 has a more continuous and less disturbed sequence. The difference in bottom-current strength is thought to be related to topographic enhancement at the southern slope of the Walvis Ridge, which forms a barrier to deep-water flow.
We expect that glacial/interglacial climatic cycles are well expressed at Site 1082 (as they are at DSDP Site 532) in terms of productivity, carbonate dissolution, and continental sedimentation cycles. From DSDP Site 532 results, we expect a general opal maximum in the late Pliocene to early Pleistocene and a silica reversal within the glacial/interglacial cycles at the end of the Miocene from high opal during glacials in the older sediments to high opal during interglacials in younger sediments. At the lower productivity levels of Site 1082, compared with Site 1081, we expect a higher carbonate content and better preservation of calcareous fossils, which will be useful in the pursuit of biostratigraphic and paleoceanographic studies, especially when comparing the responses of siliceous and calcareous plankton with climatic change. In addition, the sediments from Site 1082 will document the supply of minerals and plant remains from land as a function of changing climate and sea level.