Geomorphology of a coastal plateau (Cotentin, Normandy): tectonic and climatic records

The Quaternary evolution of Cotentin, (Normandy, France) is documented thro ugh two types of investigations: geomorphology and sedimentology. The Coten tin geomorphic system is divided into three plateaux gently dipping towards the coast. Quantitative morphometry of drainage network indicates landform rejuvenation and uplift of the South Cotentin area. Fault scarps are recog nized between the three topographic zones. They coincide with seismic linea ments and generate knickpoints along thalweg profiles or modify the sinuosi ty of the lower part of the alluvial channel. The evolution of western Norm andy during Pleistocene time is presented. The early Pleistocene environmen t is initially marine and cold. The environment then becomes fluviatile wit h a tectonic control on continental sedimentation. Finally, floodplain silt s and pears were deposited in an anastomosed river system which persists ac tually.