Fault-style analysis and seismic interpretation: Implications for the structural issues of the South-eastern Atlas in Tunisia

The aim of this paper is to clarify the structural evolvement of the study area which lies on pre-shaped substratum tectonic movements related to active faults on the eastern branch of the northern Chotts range, which is part of the southern end of the Atlassic folded structures. However, we propose a new structural model to clarify the junction between the Zemlet Baeida Structure (ZBS), the Jebel Itama structure and the first order dextral Fjej corridor fault. We then continue by analyzing the geometry and structures with detailed surface geologic data mapping, oil exploration well data, the analysis of available seismic data, and the interpretation of folding related to faulting evolutions. The geological and geophysical examination enables us to propose an innovative geometrical representation of the trough in the eastern branch of the northern Chotts range. The structural evolvement progressed from an extended event, attested by the development of a graben, passing through a period of reactivation of the inherited faults during the Atlas stress related to en echelon folding. The partitioned structure linked to the folding creates a subsided area and consecutive steps of faulting-detachment-folding. In this study we focus on tectonic inheritances that might guide the structural patterns and kinematics related to the N140 dextral strike-slip Gafsa fault. To obtain the related sources and scales, a geophysical and structural analysis of the surface and subsurface was used since it offers a good understanding of the shape and the kinematics of the systems in this area. This original structural interpretation aims to clarify the structural evolution and kinematic events and to re-evaluate the data presented to confirm that the studied trough system can be recognized during three major consecutive events: the Aptian, the Oligocene-Miocene and the Villafranchian. •Tectonic evolution shows a new structural framework with related sources and scalars.•A detachment/dislodgment and restraining bends has been identified.•Varied faults and halokinisis was clarified the evolution of this part of Atlas.•Sedimentary beds are related to stratigraphic pinch-outs at the edges of the basin.