The study of microstructures on the Boroujerd granitoid (western Iran)

Boroujerd plutonic complex is a part of Sanandaj – Sirjan structural zone which is located in western Iran. The dominant lithologic units are granodiorite that accompanied with small a –quartz diorite and monzogranitie stocks. The purpose of this research was to study the microstructure in this complex zone. Based on microscopic studies of microstructures, four type of microstructures have been identified: 1-magmatic microstructures, commonly observed in south–west of complex where its known as a Goosheh, 2-high–temperature solid–state microstructures observed in east and south–east toward the center of complex, 3- low–temperature solid–state microstructures in center, which are extended toward the west and south–west and finally 4- mylonitic to submylonitic microstructures that are extended from center to the north. Concentration of deformation intensity in north and west of complex can be attributed to existence of shear zones and faults in these regions, while magnetic microstructures in Goosheh granite indicate that tectonic forces could not affected these rocks, which can be correlated with their age that are young.