Abstract
Abstract Several high-resolution (SPARKER) seismic-reflection surveys, associated with 450 dredgings and 75 Kullenberg core samplings, allowed the definition of the main Quaternary sedimentary bodies of the Cameroon shelf. The distribution of the Holocene mantle is very uneven: its thickness reaches 40 m at the northern end of the shelf where there are sandy stratified deposits in the lower part and a High System Tract in the upper part. These deposits cross obliquely offshore and towards the south where the Holocene is either absent or localized as backfill in low-level ravines. This distribution is controlled by the Sanaga flow deflected northwards by the predominantly SW swell and by the Niger River flow driven southwards by the Guinean current. The sensu lato Pleistocene mantle is substantial in the north where fluvio-deltaic sands issued from the Nigerian complex. Southward coarse sands from the Sanaga-Nyong complex accumulate in progradient structures. In the southern part of the plateau, the Cenozoic-Mesozoic and Pre-Cambrian substratum at the outcrop is indented by extensive unevenness defining asedimentary shoals and Pleistocene-silted depressions. These depressions present paralic littoral successions towards the coast and circa-littoral to littoral successions seawards. As a result of the last eustatic movements, the roof of these successions has been planed off and has been more and less intensely modified. In some cases it is possible to date the last oscillations of the shoreline, using 14 C.
Published Version
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