Fabric analysis and investigation of geometric symmetry in the Tange Koraki shear zone, southeastern Eghlid

Study of structural fabrics as the shear sense indicators of the shear zones are an important instrument for study and determination sense of shear. Definition of geometry of shear zones will help to understand structural evolution of shear zones. Determination of vorticity vector based on the 3-D structural studies in many cases is very difficult. Study of lineations, foliations and shear zone boundaries and vorticity normal section are important and will help to understand the geometry of shear zones. In this paper, using of theoretical aspect of shear zones the main parameters of shear zones geometry has been studied. Moreover for determination of shear indicators and deformation geometry we carried out a case study in the area that is located in the Sanandaj-Sirjan HP-LT metamorphic belt. Our results show dextral sense of shear and scattering of lineation and pole of foliation around vorticity normal section. Also the stereographic analysis of structures shows a triclinic geometry for the study area. Finally we suggest the triclinic inclined transpression model for structural evolution of this shear zone.