Syn-sedimentary tectonic control of the Cretaceous deposits in the Chotts basin, southern Tunisia: Geodynamic significance

Abstract

The Cretaceous sedimentary succession of the Chotts basin in southern Tunisia is characterized by an important variation of facies and thickness controlled by N–S and E-W trending fault networks. The N–S faults are well distinguished in the Chott basin during Aptian-Albian extension, particularly in its southern part. It is E-W elongation verified by downthrow and series thickening of West compartment. On the other hand, the E-W fault or “Chotts faults” which outlined the Chotts depression was widely controlled the thickness and facies distribution of the Cretaceous deposits. This master fault was controlled the anticlinorium structure of the Chotts basin and constituted a structural limit that divides the Atlas belt to the north from the Saharan platform to the south.The detailed investigation of the major faults throughout the Chott basin reveals the importance of the Aptian-Albian extensional phase with considerable fault throw.The interference between N–S and E-W faults directions, associated to halokinesis movement contributes to the emergence of the Zemelt Elbeidha- Jebel Aziza paleohigh structure during the Aptian-Albian extensional phase. This latter tectonic event causes the sedimentary hiatus recorded during the Aptian-Albian transition over a large area of the Chotts basin and southern central Tunisian Atlas.