On the eastern edge of the Aquitaine Basin, the Lias-Dogger transition and the events, which occurred during this time interval are studied in the Quercy sedimentary basin. Stratigraphic correlations are proposed using a biochronological calibration based on the determination of numerous ammonites and brachiopods. Facies analyses using statistical processing integrate the presence of faults and tectonic compartments and lead to reconstruction of palaeoenvironments in space and time. The paper includes the description of system tracts following Haq et al.  and Vail et al. , and twelve palaeogeographic maps of the area studied. The objectives are to distinguish the various allocyclic and autocyclic factors controlling sedimentation and to show the impact of the Mid-Cimmerian tectonic event on the evolution of the basin.