Tectonics
Babak Samani
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 ...
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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.
Tectonics
Babak Samani
Abstract
In this research, using deformed chert nodules in the calcareous units of Sarvak Formation in Pyun anticline, quantitative strain values in different parts of this anticline have been investigated. In a perpendicular fold axis survey, the anticline was divided into seven different areas. At least 40 ...
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In this research, using deformed chert nodules in the calcareous units of Sarvak Formation in Pyun anticline, quantitative strain values in different parts of this anticline have been investigated. In a perpendicular fold axis survey, the anticline was divided into seven different areas. At least 40 nodules were measured in each area and finite strain analysis was carried out using Rf/Ø and polar methods. The results of strain studies show an increase mode in strain values from the fold limbs (Rs = 1.7) to the fold hinge (Rs = 2.9). Kinematic vorticity analysis shows the range between 0.68<Wk<0.91 and the effect of both simple and pure shear strain components and the occurrence of the strain partitioning in the Pyun anticline. The amounts of kinematic vorticity number indicate the increase of pure shear strain components in the hinge of anticline and the predominance of simple shear strain components in the limbs of the Pyun anticline. According to the results of strain analyses the amounts of bulk shortening was estimated about 47- 50 percent in the Pyun anticline.
