Paleozoic geological evolution of Southeastern Tunisia, North Africa: New insights from subsurface data

This study documents the Paleozoic events and their impact on the geological evolution of the Jeffara Basin and the Dahar High. Nine regional seismic profiles were interpreted, revealing the Paleozoic sedimentary record across the region. The geological history comprises two distinct periods: the early Paleozoic consisting mainly of sandstone and shale, and the late Paleozoic rich in carbonate sequences. Structurally, two different basins, separated by a structural high, were identified. We reconstructed the geological evolution of the area, focusing on the major unconformities. We described several tectonic events that resulted in the Dahar High uplift and the Jeffara Basin development. Extensional tectonic phases prevailed in the region during the Cambro-Ordovician, while compressional events and structural inversion affected the area during Devonian, Carboniferous and Permian. Four major unconformities (Taconic, Caledonian, Hercynian and Permian unconformities) outline these tectonic events. These deformations are superimposed onto the global tectonic events. The results of this study also show that the uplift of the Dahar High is proven to be a polyphase progressive uplift that was initiated since at least the Taconic event and reactivated during major tectonic phases. Finally, the uplift of the paleohigh has affected the petroleum system evolution of the surrounding basins. Stratigraphic and structural traps were proven around the high and they constitute potential plays.

Automated summary

This study investigates the Paleozoic events and their influence on the geological evolution of the Jeffara Basin and the Dahar High. Nine seismic profiles are interpreted, providing insights into the Paleozoic sedimentary record. The geological history is divided into two distinct periods: the early Paleozoic comprising sandstone and shale, and the late Paleozoic dominated by carbonate sequences. Two separate basins with a structural high in between are identified. The study reconstructs the area's geological evolution, highlighting major unconformities and tectonic events.