Petrology and geochemistry of felsic to mafic plutonic rocks from the Saheb, West Iran

There are several intrusive plutons in the Saheb- Yapesh-khan area, which are compositionally made from mafic to acidic rocks, including granite, tonalite, syenodiorite, monzodiorite, quartz diorite, diorite and to a lesser amounts gabbros. The main rock type of the area is granite. The intrusive rocks were formed at the Island- Arc (ACM) environment in terms of tectonic setting. The parental magma was primitive and formed by low degree partial melting (less than 5%) of metasomatized mantle with spinel- garnet- phlogopite lherzolite composition. The mantle source was metasomatized by influx of dehydration of sediments and the rocks of the subducting oceanic slab. The crustal contamination had a meager effect on modification of the original magma composition. On the basis of variation diagrams of the studied igneous rocks, there are two main petrogenetic trends (mafic and felsic series) for the studied intrusive rocks. It seems that these trends are formed due to fractional crystallization and separation of amphibole and plagioclase from the primary magma.