Petrography, petrology, geochemistary and petrogenesis study of amphibolites in Bahram Gor area at northwestern of Gol-e Gohar mine in Sirjan

The study area is a part of the Sanandaj-Sirjan zone which is mainly composed of metamorphic rocks, a variety of igneous basic rocks and sediments. the metamorphic rocks studied at Bahram Gur area (west of Kheyrabad, Northwestern of Gol-e Gohar mine) in Sirjan, Kerman Province are slate, phyllite, schist (garnet schist, amphibole schist, micaschist, kyanite schists), epidote amphibolite, amphibolite, gneiss, quartzite and marble. Amphibolite facies is the highest metamorphic grade in the region experienced by the rocks. Protolith of amphibolites is basic to intermediate igneous rocks with chemical composition of tholeiitic to calc-alkaline. . Based on Zr / P2O5 against Nb / Y diagram amphibolite protolith is from oceanic crust. Based on Ti against V diagram, amphibolites of the study area belong to mid-ocean ridges (MOR) and Volcanic arc tectonic environments in relation to Neotethys ocean. Primary magma of igneous rocks that are protholite amphibolite is derived from the spinel-peridotite. The negative anomaly of Nb and low Nb/U ratio indicates the contamination of this magma during rising.