Structural analysis of Siah-Jakouk area, South-east Zahedan, Sistan Suture Zone

The Siah-Jackouk area is located in the eastern part of the Sistan Suture Zone, southeast of Zahedan. This area has been affected by faulting, folding, bouddinage and dyke swarm. The main objective of this research is to display the deformation history of this area. For this purpose, the characteristics and spatial relationships of the structures were extracted, and the state of stress during the emplacement of the dykes was investigated using the 3D Mohr and stereographic methods. Statistical analysis and the cross-cutting relationships, as well as the geometry of the folding and boudinaged structures, suggest four main phases of deformation due to progressive deformation in this region. At first, the initial horizontal layering is inclined. Then the dykes penetrate along their weak surfaces, subsequently layering with parallel dykes, undergo shear component along that caused folding and bouddinage. At this phase, changes in the distance and thickness of dykes as resistant areas, have led to different evolutions of folding and faulting, and strain. In the last phase of deformation, the study area is affected by the north-south right-lateral faults caused by the current north-south stress regime of the Sistan Suture Zone.