A. Yassaghi; H. Narimani; M. Gh. Hasan goodarzi
Abstract
Structures in fold-thrust belts such as Zagros which are developing mainly along the belt strike often terminate at the transverse structures. The Zagros Mountain Front Fault has cut and displace at different parts by transverse structures. At Dowgonbadan area this fault is intersected by the Kharg-Mish ...
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Structures in fold-thrust belts such as Zagros which are developing mainly along the belt strike often terminate at the transverse structures. The Zagros Mountain Front Fault has cut and displace at different parts by transverse structures. At Dowgonbadan area this fault is intersected by the Kharg-Mish transverse structure. The Mish anticline has transported fault propagation geometry and located on hanging wall of the Mountain front fault. The anticline plunges and rotates when it reaches to the Kharg-Mish transverse fault to the west. In the fault footwall, however, the Dil, Pahn, Sarab and Jafarabad anticlines have rounded geometry and low amplitude show characteristics of the Dezful Embayment zone folds. The Dil and Pahn anticlines with bifurcate geometry and outcrop of Asmari Formation develop parallel to the frontal ramp strike and show footwall anticlines that propagated from the frontal ramp at Dashtak formation as delay structures with respect to the hanging wall structures. The Kharg-Mish fault identify as a lateral ramp on the surface by termination of longitudinal structures and at the depth with thickness and facies changes of the Ilam Formation. The structural characteristics of the Dowghonbadan area in the Zagros Fold-Thrust Belt are analyzed as the interaction of the Mountain Front fault and the Kharg-Mish transverse fault as the frontal and lateral ramps, respectively.
Z. Davoodi; A. Yassaghi
Abstract
Geometry and kinematics analyses of structures developed along one of the transverse fault zone (Izeh) in the Zagros fold-thrust belt has been presented to document the origin and to present the effect of this fault zone on the belt structures. Surface deformation of Izeh fault zone on the cover sediments ...
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Geometry and kinematics analyses of structures developed along one of the transverse fault zone (Izeh) in the Zagros fold-thrust belt has been presented to document the origin and to present the effect of this fault zone on the belt structures. Surface deformation of Izeh fault zone on the cover sediments are including changes on the Zagros major structures trends and development of minor structures (such as minor folds and faults) that are overprinted on the belt major structures. Detaeled structural mapping showed the precense of three major restraining zones between the mapped subsurface en-echelon faults along the Izeh fault zone in the Zagros fold-thrust belt. Analysis of isopach maps, facies variation of formations together with interpretation of seismic reflection profiles showed that these subsurfase faults are younger orders of the Izeh fault zone reactivation as a basement fault. Oblique convergence of the Arabian Plate toward the Central Iran is in favor for the reactivation of the fault zone and formation of surface deformations along it. Based on earthquake data this reactivation is continuing until the present time. The result of this study can be used for interpretation of deformation on the sedimentary cover along the similar transvers fault zone in the Zagros fold-thrust belt.
