Biochronologie et corrélation des bassins néogènes du Couloir sud-rifain (Maroc) fondées sur les évènements de foraminifères planctoniques et de nannofossiles calcaires

Qualitative and quantitative analyses of planktonic foraminifera (completed by calcareous nannofossils in some localities) from 8 sections and boreholes located in 7 Neogene basins of the South Rifian Corridor (Morocco) enable us to identify 16 bioevents calibrated with the geomagnetic polarity time scale. These events are useful for (1) assigning the sediments to the Tortonian (bioevents 1 to 7), the Messinian (bioevents 9 to 14, the event 8 indicates the Tortonian/Messinian boundary), the Early Pliocene (bioevent 15) and the Middle Pliocene (bioevent 16), (2) establishing high resolution correlations between the sections and boreholes studied herein, (3) locating the South Rifian Corridor sections and boreholes within the framework of biostratigraphic events recognized during the latest ten years in time-equivalent Atlantic and Mediterranean sequences, and (4) estimating the variation of sedimentation rates in the studied basins. With respect to Morocco, previous detailed studies concerned only the Rabat area (Bou Regreg valley) and Guercif basin. Our results extend correlations to the other basins of the South Rifian Corridor, a key area to understand connections between the Atlantic Ocean and the Mediterranean Sea at the end of the Miocene.