Petrology, geochemistry and tectonic setting of the Kolah Ghazi granitoid (southeast of Isfahan)


1 School of Geology, College of Sciences, University of Tehran, Tehran, Iran

2 Department of Geology, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran


The Kolah Ghazi granitoid is one of the main upper Jurassic intrusion in the Sanandaj-Sirjan zone which intruded Jurassic shale and overlaid by Lower Cretaceous strata’s. The intrusion consists of the monzogranites, granodiorites, Syenogranites, aplitic dykes associate with several tourmaline veins in three separated outcrops. Based on petrographic studies quartz, plagioclase, biotite and alkali feldspar are present as the major minerals and andalusite, sphene, tourmaline, garnet, sillimanite, spinel, kyanites constitute minor mineral phases. Geochemical results show high-K calc-alkaline and peraluminous affinities and S-type. The Kolah Ghazi granitoid belong to subduction-related volcanic arc magmatism, which related to middle Cimmerian compression movement which derived from Partial melting of metapelites in the upper crust materials and emplaced at depths (about 20-30 Km) under low water-vapor pressure (0.5-1 Kbar) and temperature range (in 750 °C)