The Controlling of Deformation Basing on Strain Partitioning Model: Case Study to Gafsa Basin (Southern Tunisian Atlas)

Soulef Amamria,Mohamed Sadok Bensalem,Mohamed Ghanmi,Fouad Zargouni

doi:10.4236/gep.2015.31004

Soulef Amamria, Mohamed Sadok Bensalem + Show 2 more

Open Access

https://doi.org/10.4236/gep.2015.31004

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Abstract

One of the principal parameters to study the tectonics deformation is the relation between the shortening axis and the direction of preexistent principal fault. It is important to verify this parameter in the belts structures. The aim of this contribution is to check this notion in the Atlassic structures, especially in the southern limit of Tunisian Atlas: Gafsa fault. The strain partitioning model proposed in the interpretation of geodynamics of Gafsa chains suggests the coexistence of thrusting and strike-slip faults during the same tectonics phase. The application of this model requires a particular geometry between the shortening axis and the direction of fault, and indeed the obliquity of preexistent faults by the reported shortening axis interprets us a transpressive context. The slickenside examination shows the coexistence of thrusting and strike-slip faults. The application of model of strain partitioning requires a decollement level which is confirmed in the Gafsa basin by the upper level of Triassic series. These parameters confirm a particular relation thin and thick-skinned and the maximum of deformation is cover, although the basement structures permeate simple passive transport of the deformation along the Triassic decollement level. These problems confirm the assumption of the evolution of the shortening axis during geological events and especially the rotation of Africa and Eurasia.

Highlights

In the North of the African plate, especially in the northern extremity of Atlassic chains, the geological struc-How to cite this paper: Amamria, S., Bensalem, M.S., Ghanmi, M. and Zargouni, F. (2015) The Controlling of Deformation Basing on Strain Partitioning Model: Case Study to Gafsa Basin (Southern Tunisian Atlas)
This zone is presented by several work (Zargouni et al, 1986 [6]; Ben Ayed, 1986 [7]; Boukadi, 1994 [8]; Bouaziz, 1995 [9]), the folds of Gafsa Basin are characterized by NW-SE direction and have a complicated geometry
In the southern Atlassic of Tunisia, the strike-slip faults are connected with the thrusting which shows that the axis of shortening is oblique with the major faults of NW-SE direction

Summary

Introduction

In the North of the African plate, especially in the northern extremity of Atlassic chains, the geological struc-. (2015) The Controlling of Deformation Basing on Strain Partitioning Model: Case Study to Gafsa Basin (Southern Tunisian Atlas). Martinez et al (1990) [4] proposed that the evolution of deformation in the Northern of the African plate was correlated with the intense téthysian activity during the tectonic phases. The southern atlas of Tunisia is the limit between two different tectonics domains This zone is presented by several work (Zargouni et al, 1986 [6]; Ben Ayed, 1986 [7]; Boukadi, 1994 [8]; Bouaziz, 1995 [9]), the folds of Gafsa Basin are characterized by NW-SE direction and have a complicated geometry. Many models are proposed to interpret the geometry of folds in the southern Atlassic limits, but they don’t resolve yet the implication of the basement in deformation. We have interest in the relationship between cover and basement, so we propose a model of evolution of structures during the tectonic phases

Geodynamics Setting

Problematic of Implication of the Basement

Relation between Thrusting and Strike-Slip Faults

Deformation in Southern Central of Atlassic of Tunisia

Discussion

Conclusions