Structural and geodynamic study in central Tunisia using field and geophysical data: new structural interpretation of the N–S axis and associated Atlassic structures

Tectonosedimentary framework of Upper Cretaceous –Neogene series in the Gulf of Tunis inferred from subsurface data: implications for petroleum exploration

“…This thickness decrease is due to the tectonic control amplified by halokinesis and ero sion as highlighted for the Abiod Formation to the northwest of the study area within the offshore well 1. The post Ypresian deposition records some compressional events especially above main normal faults in testimony of their Neogene inversion as occurred in the Northeastern Tunisia and the Pelagian province after the Africa-Europe convergence (Morgan et al 1992;Guiraud 1998;Piqué et al 1998;Brunet & Cloetingh 2003;Melki et al 2010;Dhahri & Boukadi 2010;Dhahri et al 2015). However, these deformations are sealed by an uppermost horizontal level Pliocene-Quaternary in age suggesting a low angle unconformity above the deformed zone (Fig.…”

“…The strata beneath the Gulf of Tunis constitute an off shore basin that developed during the Neogene Africa-Europe collision (Dart et al 1993;Lentini et al 1996;Catalano et al 2011). The geological history of this area is linked to the evolution of the North African margin guided by transten sional plate movements between Africa and Eurasia during the Mesozoic, followed by plate collision during the Neogene (Stampfli & Borel 2002;Brunet & Cloetingh 2003;Patriat et al 2003;Laville et al 2004;Abrajevitch et al 2005;Dhahri & Boukadi 2010;Melki et al 2010;Catalano et al 2011;Roure et al 2012;Masrouhi et al 2014;Dhahri et al 2015). The architecture of the Gulf of Tunis basin developed mainly during the Mesozoic, and then was greatly deformed during the Neogene leading to the inversion of extensional structures and to the redistribution of subsidence locations.…”

The role of E–W basement faults in the Mesozoic geodynamic evolution of the Gafsa and Chotts basins, south-central Tunisia

“…Gravity data modeling showed that Paleozoic series are ∼2500 m thick and rest at ∼7000 m depth (Hlaiem 1998). In central Tunisia, Triassic series mainly outcrops along the Mezzouna corridor and N-S axis chain (Burollet 1956;Boukadi et al 1992;Boukadi and Bédir 1996;Azaïez et al 2007;Dhahri et al 2015;Dhahri and Boukadi 2017). They consist of mixed gypsum, clay, silt and dolomite, well documented northward in the Rheouis Formation (Burollet 1956;Soussi et al 1997Soussi et al , 2001Courel et al 2000).…”

“…In Tunisia, the activity of main N-S and E-W faults began for the most before the Triassic. In the Tunisian central and southern Atlas, these latter have controlled basin configuration and distribution of deposition during the Jurassic and Cretaceous (Ben Ayed 1986;Ben Ismaïl 1991;Chihi et al 1992;Bédir 1995;Zouari 1995;Zitouni 1997;Ben Timzal 2000;Bédir et al 2000Bédir et al , 2001Bouaziz et al 2002;Abbes 2004;Gabtni et al 2005Gabtni et al , 2006Gabtni et al , 2011Azaïez 2011;Said et al 2011;Ahmadi et al 2013;Dhahri et al 2015;Gharbi et al 2015). A transtensional regime prevailed until Early Cretaceous and was presumably disturbed by a regional NW-SE transpressional-event followed by a transpressional regime during Late Aptian-Early Albian times (Guiraud et al 1987;Rabhi and Ben Ayed 1990;Bédir 1995;Bédir et al 2001;Bouaziz et al 2002).…”

“…A transtensional regime prevailed until Early Cretaceous and was presumably disturbed by a regional NW-SE transpressional-event followed by a transpressional regime during Late Aptian-Early Albian times (Guiraud et al 1987;Rabhi and Ben Ayed 1990;Bédir 1995;Bédir et al 2001;Bouaziz et al 2002). This regime prevailed during the Late Cretaceous until the onset of the tectonic inversion of the Atlasic domain initiated at the Cretaceous-Cenozoic transition as a result of the Africa-Europe convergence leading to two main shortening episodes during the Eocene and Mio-Pliocene (Boukadi et al 1992;Morgan et al 1992;Piqué et al 1998;Brunet and Cloetingh 2003;Khomsi et al 2006;Malusa et al 2007;Masrouhi et al 2008;Boukadi 2010, 2017;Roure et al 2012;Dhahri et al 2015). The Gafsa and Chotts domains, subject of this study (figure 1), constitute the eastern extend of the Algerian Atlasic chain limited to the south by the South Atlasic Front (Busson 1967;Outtani et al 1995;Bracène and Frizon de Lamotte 2002;Gabtni et al 2005;Malusa et al 2007;Frizon de Lamotte et al 2009).…”