文摘
This paper discusses the Neogene tectonic evolution using an integrated approach of field observations and microtectonic study supported on seismic data and well data arguments, carried out on the Chaouat-Mannouba area (Northern Tunisia). This allowed highlighting an elbow-shaped graben with two branches oriented NW-SE and E-W. During the Neogene, the study area was affected by geodynamic interactions controlled simultaneously by convergence of the Eurasian and African plates. These interactions generated both compressive and extensional regimes which led to a variety of structures. Palaeostresses and deformation axis reconstruction related to the Chaouat-Mannouba area evidences two tectonic episodes. The first, of Aquitanian-Tortonian age, consists in an extensive regime associated with a strike-slip deformation. The second is upper Miocene to Quaternary age; the study area has been affected by two compressive regimes oriented NW-SE and N-S associated with strike-slip deformation. This Neogene kinematic reconstruction highlights the neotectonic system inducing the paleoseismic events and the actual seismicity in northeastern Tunisia which might be related to tectonic fault reactivations. The study of the chronology deformations in Chaouat-Mannouba area allows better understanding the recent geodynamic evolution of the Greater Tunis (Northern Tunisia) in the context of the foreland basin of the Tunisian Alpine chain. Keywords Northern Tunisia Neogene Graben Seismites Neotectonic