Atlantic-Type Passive Margin Structural Style of the Cretaceous Basin inNorthern Tunisia: Paleoslope Reconstruction and Regional Tectonics
Résumé
The purpose of this paper is to characterize the configuration of northern Tunisia’s basin during the Cretaceous on the basis of abundant slump folds and frequent synsedimentary faults. The slump folds are studied to determine the slumps transport vergence on the synsedimentary submarine paleoslope. The local and regional stress field is used to characterize the syn-sedimentary deformation. During Valanginian–Aptian times, the basin is characterized by southward submarine slope. From Albian to Santonian times, the slump folds analysis provides NNW- to NW-ward sloping topography. The fault kinematic analysis reveals regional NW- to NNW-trending Cretaceous tectonic extension. Locally, NE- to N-trending extension is characterized. Perturbation of paleoslope orientation is locally observed probably related to salt tectonics hyperactive during Aptian–Albian. The constructed regional cross-section shows a tilted block geometry governed by major basement faults associated to other intra-basin growth faults. The basin shows ±5° seaward facing submarine paleoslope. In addition, some structures are probably dominated by raft tectonics. All these features are fairly consistent with the conclusion that the basin is very similar to the present-day Atlantic-type passive margins
Domaines
Tectonique
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