Geological Study of the Early Pleistocene Site of Senèze (Domeyrat, Haute-Loire, France)

The fieldwork carried out on the Senèze deposits between 2001 and 2006 allowed a detailed stratigraphic analysis of their nature and geometry. The emplacement of phreatomagmatic beds related to maarMaar formation was followed by deposition of prograding lenses of more or less coarse sediments, originating from the reworking of outcrops located around the crater. These slope layers are covered by lacustrine layers, occurring between 625 and 620 m altitude. Marked differences in sedimentation found across sectors of the site are due to the morphological context (stiffness of the slopes of the maarMaar), the nature of the underlying outcrops (gneissic basement, volcanic products), syn-sedimentary deformations (load casts, collapse faults, mass slip) and climatic changes leading to variations in the water level of the paleo-lake. This sedimentary context allows a better understanding of the genesis of the paleontological assemblages.