Apport des ostracodes à l’interprétation séquentielle du Crétacé inférieur (Berriasien–Valanginien) du bassin d’Essaouira–Agadir (Maroc)

Contribution of the ostracods to the sequential interpretation of the Lower Cretaceous (Berriasian–Valanginian) of the Essaouira–Agadir Basin (Morocco). The analysis of the ostracod fauna from the Berriasian–Valanginian of the Essaouira–Agadir Basin (Morocco) allows us to make a narrow relationship between the sequential evolution (established on sedimentary, biostratigraphical and geochemical data) and the evolution of statistical parameters of ostracods. So, the number of individuals and the number of species present comparable fluctuations and follow perfectly the sequential evolution; classes of dominant and fortuitous frequency are the most meaningful, the specific renewal rate shows extremes values at the limits of sequences and at the basis of transgressive systems tracts.