HR: 1340h
AN: T53C-1436    [Abstracts]
TI: Analysis of Fold- and Fault-related Fractures in the Zagros Range, SW Iran, Applying GIS and Remote Sensing
AU: * Mobasher, K
EM: kmobasher1@student.gsu.edu
AF: Katayoun Mobasher, Department of Physics, Astronomy & Geology Berry College 2277 Martha Berry Hwy NW , Mount Berry, GA 30149 United States
AU: * Mobasher, K
EM: kmobasher1@student.gsu.edu
AF: Hassan A. Babaie, Department of Geology Georgia State University P.O. Box 4105 , atlanta, GA 30302-4105 United States
AU: * Mobasher, K
EM: kmobasher1@student.gsu.edu
AF: Shuab D. Khan, Department of Geosciences, University of Houston, 312S & R1 , Houston, TX 77204 United States
AB: We have applied various enhancement methods on satellite imageries to study the fold- and fault-related fracture systems in the Zagros fold-and-thrust belt, in SW Iran. These methods facilitated the identification and mapping of fracture traces. Bands 3, 2, and 1 of VNIR subsystem of ASTER imagery, and bands 1, 5, and 4 of ETM imagery, assigned as red, green and blue, respectively, were found to be the most useful for both geological and structural interpretations of the images. Among the methods applied, the texture analysis, image inversion, 3D perspective views, and histogram equalization methods proved to be the best enhancement methods for delineating the fractures. The histogram equalization, 3D perspective views, image inversion and supervised image classification were successful in discriminating different lithologies and fold structures. Other methods such as the principal component analysis, high-pass filtering, and unsupervised image classification, proved to be relatively less useful in enhancing the surface fracture traces. The fracture traces around the Kazerun fault, a major strike-slip fault, as well as in several adjacent anticlinal fold structures, were digitized and stored as poly-lines in a GIS geodatabase. The results of the fracture analysis in the folds indicate four principal fracture orientations relative to the fold axial traces: (i) an axial set, defined by normal faults, parallel to the fold axial trace; (ii) a cross-axial, tensile (T) fracture set, perpendicular to the axial set; (iii) two sets of oblique, intersecting shear fractures (shear 1 and shear 2), at acute angles, and symmetric, to the cross-axial set. The fracture system around the trace of the right-lateral Kazerun fault includes: (i) two sets of Riedel (R, R1) shear fractures, (ii) a set of tensile (T) fractures, (iii) an oblique set of shear fractures (P), at a low angle to the main Kazerun fault, and (iv) a set of displacement shear fractures (Y) parallel to the main fault. The major axial and cross-axial fold-related fracture sets are oriented 139° ±9° and 052° ±6°, parallel to trend of the Zagros fold and thrust belt and the corresponding shortening direction, respectively. The shortening direction, resolved from the fault-related fractures of the Kazerun fault, is oriented 048° ±5°. Both of these shortening directions are consistent with the current SW-NE convergence of the Arabian and Eurasian plates.
DE: 8011 Kinematics of crustal and mantle deformation
DE: 8040 Remote sensing
SC: Tectonophysics [T]
MN: Fall Meeting 2005