Analyse biostratigraphique et sédimentologique des séries éo-oligocènes et miocènes de la Tunisie septentrionale : implications stratigraphiques et géodynamiques

Abstract: The new biostratigraphic, sedimentological and structural data confirm the allochthony of the Numidian flysch and suggest the existence, in northern Tunisia, of two different allochthonous units within the so-called Numidian flysch as well as several underlying small-scale Tellian tectonic units. The first unit, mainly composed of sandstones and then by “silexites” corresponds to the Kroumirie and Babbouch members, extends from Late Oligocene to Aquitanian. It rests tectonically on the unit predominantly composed of claystones with sandstones of the Zouza member which is of Early Oligocene to Aquitanian. The Zouza member, which is at least 1800m thick, extending from Oligocene to Early Miocene, should be considered, at least partly, coeval to the Kroumirie member considered in the classic stratigraphic scheme as the middle part of the flysch. In this study, we demonstrate also that the deposits of the Numidian flysch and those of the Tellian and Bejaoua group, outcropping to the south, do not belong to the same sedimentary system. Their current juxtaposition resulted from the thrusting of the Numidian flysch southwards during the inversion phase that accompanied the convergence of Africa and Europe. [Copyright &y& Elsevier]