Structural evolution of Cenozoic basins in northeastern Tunisia, in response to sinistral strike-slip movement on the El Alia-Teboursouk Fault

• Published in: Journal of African earth sciences (1994) Vol. 134; pp. 174 - 197
• Main Authors: Bejaoui, Hamida, Aïfa, Tahar, Melki, Fetheddine, Zargouni, Fouad
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-10-2017; Elsevier
• Subjects: Cenozoic; Earth Sciences; El Alia-Teboursouk Fault; Folds; Sciences of the Universe; Seismic; Tectonics; Tunisia; Wells; Folds; Cenozoic; Wells; Tunisia; Seismic; El Alia-Teboursouk Fault
• ISSN: 1464-343X; 1879-1956
• DOI: 10.1016/j.jafrearsci.2017.06.021

This paper resolves the structural complexity of Cenozoic sedimentary basins in northeastern Tunisia. These basins trend NE-SW to ∼ E-W, and are bordered by old fracture networks. Detailed descriptions of the structural features in outcrop and in subsurface data suggest that the El Alia-Teboursouk Fault zone in the Bizerte area evolved through a series of tectonic events. Cross sections, lithostratigraphic correlations, and interpretation of seismic profiles through the basins show evidence for: (i) a Triassic until Jurassic-Early Cretaceous rifting phase that induced lateral variations of facies and strata thicknesses; (ii) a set of faults oriented NE-SW, NW-SE, N-S, and E-W that guided sediment accumulation in pull-apart basins, which were subject to compressive and transpressive deformation during Eocene (Lutetian-Priabonian), Miocene (Tortonian), and Pliocene-Quaternary; and (iii) NNW-SSE to NS contractional events that occurred during the Late Pliocene. Part of the latest phase has been the formation of different synsedimentary folded structures with significant subsidence inversion. Such events have been responsible for the reactivation of inherited faults, and the intrusion of Triassic evaporites, ensuring the role of a slip layer. The combined effects of the different paleoconstraints and halokinetic movements are at the origin of the evolution of these pull-apart basins. The subsurface data suggest that an important fault displacement occurred during the Mesozoic-Cenozoic. The patterns of sediment accumulation in the different basins reflect a high activity of deep ancient faults.
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•Study area is the seat of a consequent polyphase shortening deformation between Eurasia and Africa.•As a consequence, Cenozoic cover appears through development of “pull-apart” basins of variable sizes and shapes.•NE to ∼EW “en echelon” Alia-Teboursouk sinistral fault network may explain the genesis and evolution of these basins.•Subsurface data, i.e. well logs and 2D seismic lines, indicate the role that may have played this major fault.•Thickness and facies distributions of Mesozoic-Cenozoic stratigraphic sequences probably controlled by shears and diapirism.