Variations in the plate convergence direction have generally reflected on the kinematics of the major fault zones developed in the intercontinental parts of the collision zones.The Kuhbanan Fault system is one of the ...Variations in the plate convergence direction have generally reflected on the kinematics of the major fault zones developed in the intercontinental parts of the collision zones.The Kuhbanan Fault system is one of the most important intercontinental faults in the Arabia-Eurasia collision zone with a dextral strike slip mechanism.This fault system is composed of three fault strands including Kuhbanan,Bazargan,and Kerman Faults.Here we used calcite e-twin analysis of the vein samples developed in these fault zones to reconstruct deformation condition and the paleodifferential stress direction and magnitude at the Kuhbanan Fault system.Our results represent 190°C-200°C of the deformation temperature and related 5–6±1 km of deformation depth at the Kuhbanan Fault system.Calculated paleodifferential stress magnitude in the Kuhbanan Fault system using e-twin parameters ranges from 169-196 MPa similar to the inner parts of the orogenic systems.Comparing the data set of the Kuhbanan Fault system with previous studies at the Zagros orogen represents an increase of deformation depth and paleodifferential stress magnitudes from the foreland of the Zagros orogen to its hinterland and finally northward around the Kuhbanan Fault system in the central Iranian blocks.We have also proposed a shift of the stress direction from paleo NE to recent N directed by comparing paleostress direction deduced from the calcite e-twin and recent stress direction calculated from GPS and earthquake data analysis around the Kuhbanan Fault system.This kinematics change due to plate reorganization is in agreement with the observed regional variation in convergence direction all in the Arabia-Eurasia collision zone.展开更多
基金financial support of Tarbiat Modares University,Iran。
文摘Variations in the plate convergence direction have generally reflected on the kinematics of the major fault zones developed in the intercontinental parts of the collision zones.The Kuhbanan Fault system is one of the most important intercontinental faults in the Arabia-Eurasia collision zone with a dextral strike slip mechanism.This fault system is composed of three fault strands including Kuhbanan,Bazargan,and Kerman Faults.Here we used calcite e-twin analysis of the vein samples developed in these fault zones to reconstruct deformation condition and the paleodifferential stress direction and magnitude at the Kuhbanan Fault system.Our results represent 190°C-200°C of the deformation temperature and related 5–6±1 km of deformation depth at the Kuhbanan Fault system.Calculated paleodifferential stress magnitude in the Kuhbanan Fault system using e-twin parameters ranges from 169-196 MPa similar to the inner parts of the orogenic systems.Comparing the data set of the Kuhbanan Fault system with previous studies at the Zagros orogen represents an increase of deformation depth and paleodifferential stress magnitudes from the foreland of the Zagros orogen to its hinterland and finally northward around the Kuhbanan Fault system in the central Iranian blocks.We have also proposed a shift of the stress direction from paleo NE to recent N directed by comparing paleostress direction deduced from the calcite e-twin and recent stress direction calculated from GPS and earthquake data analysis around the Kuhbanan Fault system.This kinematics change due to plate reorganization is in agreement with the observed regional variation in convergence direction all in the Arabia-Eurasia collision zone.
