Les environnements continentaux du corridor rifain (Maroc) au Miocène supérieur d'après la palynologie

Till now the vegetation and climate of the South Rifian Corridor were poorly known. In order to document this problem seven outcrops or boreholes from the middle Tortonian to early Messinian have been analysed along this South Rifian Corridor. Two of these are presented here. The pollen contents found in those levels allow reconstructing the vegetation landscape and the climate at this Mediterranean latitude. An Avicennia mangrove lived on the coastline and a sub-desert herbaceous cover lived at a low altitude. Forests were developed in middle altitude. Climate was tropical to subtropical, very dry near the coast but more humid at higher altitude. The Poaceae/Asteraceae ratio show that aridity has even slightly increased in the South Rifian Corridor during the early Messinian. Those results confirm that climate was warm and dry a long time before the Messinian salinity crisis.