Structural Analysis of Dehnow Anticline, an Evidence for the Effects of Subsurface-Transverse Faults on Fold Geometry of Zogros Fold-Thrust Belt

NW-SE trending Dehnow anticline located between Hendurabi and Razak lineaments and in hangingwall of Mountain Front Fault (MFF), has prominent characteristics such as existence of thrust faults on either limb, box shape at depth and occurrence of two minor anticlines in en-echelon array. In this paper, structural geometry of the anticline and the effect of subsurface-transverse lineaments on its geometry are presented using field data, satellite images and available seismic-reflection sections. Fold style of the anticline is affected by Salt Hormuz series, as a regional detachment layer. The fault detachment fold style of the anticline has been analyzed using seismic sections and structural data. The effects of regional deep-seated transverse structures such as Hendurabi and Razak Lineaments on structural geometry of the anticline were also investigated. Accordingly, a NW-SE trending subsurface transverse-shear zone was inferred in region. This shear zone caused development of en-echelon array set of fractures and folds in the interior of the anticline and counterclockwise rotation of its axis. It is suggested that this transverse-shear zone is the southern continuation of Sabzpoushan transverse fault zone. NE-SW trending Hendurabi lineament which was conformed to have a sinsteral fault zone causes clockwise rotation of the anticline axis. No structural evidences on the effect of the Razak lineament have been recognized in Dehnow anticline.