Document Type : Original Research Paper

Author

• Babak Samani

Faculty of Earth Sciences, Shahid Chamran University of Ahvaz

Abstract

The use of spatial orientation of structural elements provides a great help to understand the geometry of shear zones. Investigating the indices of non-axial deformable flow in two areas of shape preferred orientation (SPO) and lattice preferred orientation (LPO) of quartz in the deformed rocks of Koli Kosh complex in the Sanandaj-Sirjan metamorphic belt at the north of Fars province show the dextral shear component. Quartz c-axis preferred orientation indicates the dominance of bulging and sub-grain rotation recrystallization in the thermal range of 379±50 to 448±50 degrees Celsius and pressure of 3 to 3.5 kbar. According to stereography projection of pole of foliation and lineation the plane of vorticity normal section was estimated as N15W/45SW. Assuming the compatibility of the north and south thrust systems with the boundary of the shear zones, the rake angle of the boundary of the shear zone and the vorticity normal section was calculated equal to 19 degrees. Therefore, it is possible to consider the oblique transpiration model with triclinic geometry as the structural evolution model of this shear zone.

Keywords

• Strain
• Bulging recrystallization
• sub-grain rotation recrystallization
• Preferred orientation
• Quartz c-axis

Main Subjects

• Tectonics