Geochemistry, tectonic setting and magmatic origin of the mineralized stock in SahebDivan porphyry copper system, NW Iran

SahebDivan porphyry copper system is located in Alborz-Azarbaijan magmatic zone at northwest Iran. Based on geological surveys, petrographic and geochemical studies, indicated that mineralized stock in this system mainly cosists of granodiorite, diorite and monzonite rocks. These rocks are peraluminous and belong to high-K calc-alkaline and shoshonitic magma series and plotted in the field of I-type granites. In Harker diagrams, SiO2 has a negative correlation with the elements of Al2O3, CaO, K2O, MgO, P2O5, TiO2, FeOt, Co, V and positive correlation with Cr, La, Zr and Nb. Enrichment in large-ion lithophile elements (e.g., Cs, Th and U), depletion of high-field-strength elements (e.g., Nb, Ta and Ti) and enrichment in light rare earth elemements than heavy rare earth elements with negligible Eu anomaly is another geochemical features of SahebDivan granitoid rocks. Tectonic setting discrimination diagrams indicate that these stock formed in a post-collision volcanic arc environment in the active continental margin. Geochemical data, indicates that partial melting of the lower continental crust due to the penetration of mantle melts in equilibrium with the residual consisting of amphibole and pyroxene and pyroxene with next function of contamination and fractional crystallizatin processes played role in the formation and evolution of this rocks. Keyword: SahebDivan, porphyry copper system, granodiorite rocks, geochemistry, tectonic setting, origin of magma. Corresponding author, Tel: 04144222720, Fax: 04144224211, E-mail: hkhalilzadeh62@gmail.com