Structural Analysis of the Western Part of Shotori Mountain Range; Eastern Iran

Abstract

NW-SE trending Shotori range has some structural elements such as folds and fractures (including thrust and strike-slip faults), following almost a similar trend. Based on the plotted stereograms, the predominant mechanism of the region’s faults is thrust with a dextral strike slip component which implies overcoming compressive stresses in the region. On the other hand the strike-slip horizontal component of the faults may also be due to the Nayband fault activities on Shotori and Esfandiar thrust zones. The steep dip of these faults may also be due to some normal faults converted to reverse faults as a result of stress phase change from tensional to compressional. Based on planar axis perpendicular compression or stretching axis σ1= 34, 10 and σ3= 296, 38 were obtained for the study area. striogram axial surface folds dominantly show NW-SE direction, which is indicates compression axis which is equal N53, 12.Aeromagnetic data analysis revealed two magnetic lineaments with the same trends as surveyed lineaments in the field. The relatively high magnetic intensity of these lineaments could be due to basement faults in the region. With regards to obtained stereo plots, trend of the folds’ axis are parallel to the regional thrust faults and folds’ contour diagrams apply asymmetric folds with faulting in the area.