Petrofabrics and microstructural characteristics of the quartz-rich mylonites were investigated in the NW–SE-trending Gol-e-Gohar shear zone with length of ca. 25 km within the Zagros Transpression Zone, SW Iran. The semi-quantitative vorticity analysis using quartz c-axis-fabric (Rxz/β method) and rigid porphyroclast geometry (Rigid Grain Net method) reveals that mean kinematic vorticity number (Wm) increases towards the Baghat Thrust Fault displaying the occurrence of spatial and temporal variations of flow during progressive deformation. The Wm values show pure shear-dominated flow progressively was changed to a simple shear-dominated flow toward to the late stages of ductile deformation, implying that the accelerating flow path was accompanied with progressive cooling and strain localization at the lower parts of the zone. The measured vertical thinning/dip-parallel elongation suggests that thrust emplacement and metamorphic rock extrusion likely occurred by a combination of simple shear with a pure shear component of deformation (i.e., general shear). The estimated deformation temperatures based on the quartz c-axis fabric patterns and their opening angles highlight greenschist-to-amphibolite-facies conditions.