Tectonics
Ali Bandegani; Ali Yassaghi; Mohsen Eliassi
Abstract
In this paper, the structural evolution of Bamu fault zone located in the Zagros folded belt zone is presented as an example of northeast-trending fault zone in the Zagros, using the kinematic and dynamic analysis of accompanied structures. Based on structural and paleostress analyzes two phases of shortening ...
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In this paper, the structural evolution of Bamu fault zone located in the Zagros folded belt zone is presented as an example of northeast-trending fault zone in the Zagros, using the kinematic and dynamic analysis of accompanied structures. Based on structural and paleostress analyzes two phases of shortening were determined as NE and NNE. In order to define the chronology of the deformation stages in the region, the relationship between fault structures and folds in the folded rock formations has been utilized. The result showed that the first compression stress trend in the area was NE that caused formation of the Bamu transverse Fault with left-lateral strike-slip mechanism and its accompanied structures. Since this stage of deformation has affected the Oligocene- early Miocene formations, more likely occurred at this time. During the next phase the shortening direction, due to change in the collision zone direction of the Arabian-central Iran in the Miocene-Pliocene, has changed to NNE which causes development of younger structures in the form of folding and reverse faulting in the fault zone. This shows that the NE-trending fault zones, like other major NW-faults, in Zagros affected by the change in the convergence of Zagros collision.
R. Arfania
Abstract
The study area, located in the east of Eghlid town, between the northeast of the Abadeh Fault and southwest of the Zagros Main Fault, consists of the highly deformed rocks, which have been emerging clearly in tectonic crashed zone. Kinematic analysis carried out for determining the paleostress directions ...
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The study area, located in the east of Eghlid town, between the northeast of the Abadeh Fault and southwest of the Zagros Main Fault, consists of the highly deformed rocks, which have been emerging clearly in tectonic crashed zone. Kinematic analysis carried out for determining the paleostress directions and deformation history of the area. Thus, the geometry of the fault plan/fault zone brittle structures and other kinematic indicators were measured based on the field observations and analysis carried out via data analysis inversion method and statistical models. The geological evidences provided necessary data for determining formation ages of the structures based on the relative time scale. According to the results, it can be concluded that three different faulting phases were efficacious in formation of the analyzed faults. During the faulting phases, three reverse fault systems developed respectively; imbricate fans thrust system, hinterland dipping duplex and inverted normal faults.