Document Type : Original Research Paper



The Ali Abad Damag granitoid is intruded in Triassic-Jurassic schists located 35km south of Hamadan, southeast of the Alvand batholith. Northeast-southwest oriented mylonitised Ali Abad Damag granitoid has been intruded into a strike-slip dextral ductile shear zone. Abundant deformed enclaves exist in this granitoid that all were strongly elongated along the main extension direction (X axis). The elongation of the enclaves is concordant with the strain rate and development of the mylonitic foliation and stretching lineation. Structural analysis of exposed rocks in this shear zone indicates that the mylonitic foliation is sub-vertical or steeply dipping to NW in the western half and shallowly to moderately dipping to the same direction in the eastern half, but the stretching lineation is sub-horizontal sub-parallel to the strike of the mylonitic foliation throughout the shear zone. Dextral strike-slip displacement is identified by the shear sense indicators. The change of foliation dip of the eastern half against the western part is interpreted by rotation along the NW-SE trending Darreh-Gar strike-slip fault.


Amidi, S.M., Alavi Tehrani, n., Gorashi, M., Sabzaei, M., 1977. Geology of the Hamadan Quadrangle. Geological Survey of Iran.
Berberian, M., & Alavi-Tehrani, N., 1977- Structural analyses of Hamadan metamorphic tectonites. In: Berberian, M. Editor, Geological Survey of Iran, Report 40Geological Survey of Iran, Report 40 (1977), pp. 239–260.
Mohajjel, M., Baharifar, A., Moinevaziri, H. & Nozaem, R., 2007- Deformation history, micro-structure and P-T-t path in ALS-bearing schists, southeast Hamadan, Sanandaj-Sirjan zone, Iran, Journal of Geological Society of Iran1, 11-19.
Mohajjel, M., & Fergusson, C. L., 2000- Dextral transpression in Late Cretaceous continental collision, Sanandaj-Sirjan Zone western Iran. Journal of structural geology, 22, 1125-1139.
Paterson Scott, R., Pignotta Geoffrey, S., & Vernon, Ron, H.,  2004. The significance of microgranitoid enclave shapes and orientations, Journal of Structural Geology 26, 1465–1481.
Ramsay, J.G., & Huber, M.I., 1983. Modern structural geology, volume 1: strain analysis. Academic Press INC. 307 pages.