New Insights of the Early Cretaceous Syn-Rift Sedimentation in the Mecella Structure (Northeastern Atlas of Tunisia): Geodynamic Evolution

Abstract

Detailed stratigraphy and facies analysis of the Early Cretaceous successions outcropping in the Mecella structure (Northeastern Tunisian Atlas), integrated with a structural analysis, allowed us to characterize the evolution of an intraplatform basin. A syn-rift tectonic is associated with the development of the major synsed-imentary normal fault systems producing the tilted blocks basin geometry in Northeastern Tunisian Atlas. Incised sandy turbidite canyon, soft-sediment deformational structures mainly represented by slumps, down-slope sliding of ancient deposits and halokinetic activity are the main features of a syn-rift intraplatform basin. The close up of this intraplatform basin history occurred in the Hauterivian and Barremian stages by the installation of a condensed shallow water carbonate platform on the higher structures. The biostratigraphic results and the facies analysis of the resedimented Triassic series allow us to ascribe the halokinetic activity to the Upper Valanginian.