Major faults, salt structures and paleo-ridge at tectonic nodes in Northern Tunisia: contribution of tectonics and gravity analysis

Structural analysis, fault kinematics, detailed geological mapping and gravity analysis provide a new approach regarding to the tectonic-model of the Bazina–Aouana structure (North–Eastern Tunisia). They show that the Bazina Triassic outcrops, such as several other structures, are related to the NE and E trending major faults junction, controlling its halokinesis, and pouring out to the NW of tectonic nodes in the collapsed compartment. During the Eocene and Tortonian compressive phases, the Triassic materials previously forming a intumescence in the NE and E major faults intersection have acted as a barrier on which collided the Aouana structure. Therefore, this structure is blocked between overthrust nappes and the Bazina paleo-ridge forming an imbricated zone overlapping the Triassic materials. This paper aims to present a new evolutionary geodynamic model for the Bazina–Aouana structure related to the tectonic node easing the Triassic salt mobilization, the paleo-ridge formation and the development of a collapsed zone. By comparing with previous works, this model is likely applicable to the important Triassic outcrops of Northern Tunisia.