Modeling of the principal parameters controlling the evolution of deformation in Atlassic belts: case study of the southern-central Tunisian Atlas

The pursuing of the evolution of such deformation in the external zone is one of the main objects geologists which necessarily require deciphering the main parameters of this evolution. The southern-central Tunisian Atlas is the most appropriate ground to check such complication, in fact, it is centered between a northern area strongly tectonized and stable southern area. Is chosen especially the juxtaposition between the two largest mountains those of Orbata and Bouhedma. The comparative study between two very close areas Jebel BouMiza and Jebel At-Taghli in the Orbata–Bouhedma junction shows a very large variation in deformation when they are subjected to the same context establishment. One of the main parameters of the variation of the deformation is the notion of inheritance tectonics associated with the reactivation of ancient normal faults during the compression and therefore the position of these faults to shortening axis. The other important parameter is the vertical migration of decolement level that is a direct consequence of the elevation of the deformation; it is the vertical migration of the deformation. Example of Jebell At-Taghli shows a much accentuated deformation in comparison with that of the deformation Jebel BouMiza, this deformation is explained by the combined activity of two faults el-Mich and At-Tagli, oblique to the axis of shortening and the reactivation dextral strike-slip fault during compressive phases. The disposition of Jebel At-Taghli defines a tear-fault structure with the development of a duplex structure associated with decollement levels in the upper series (Bouhedma Formation).