Seismic stratigraphy and cenozoic evolution of the mesetan moroccan atlantic continental shelf

A recent high-resolution seismic survey of the El Jadida continental shelf allows the characterization of the Cenozoic evolution of the Northern Atlantic Moroccan Shelf, which belongs to the Western Meseta structural domain. Seismic stratigraphy indicates a subdivision of the Cenozoic deposits into four sequences (Sca1 to Sca4) restricted to the northern portion of the shelf. Chronostratigraphic identification of the sequences shows that principal deposits correspond to Upper Miocene deposits overlying the Cenomanian carbonate platform. Quaternary deposits are restricted to the lowstand sedimentary wedge extending below a water depth of 130m and to the last highstand system tract corresponding to the Oum Er Rbia prodelta. Cenozoic evolution of the continental shelf was controlled by a combination of pluvial/interpluvial stages and eustatic fluctuations, but also by local tectonics. Terrigenous sediments built up the Oum Er Rbia prodelta during the estimated time interval 6–2ka coinciding with stabilisation of high sea level and pluvial stage. Tectonic deformations occurred mainly during the Upper Miocene and accentuated shelf subsidence through reactivation of inherited N20°/N40° and N140° faults in response to the Europe/Africa collision. Some of the N140° faulting zones are still active during the Quaternary. Currently subsidence has ceased and a broad uplift of the greater part of the continental shelf probably occurs. [Copyright &y& Elsevier]