Petrology, geochemistry and tectonic setting of the intrusive mass associated with Rangraz copper deposit (North of Saveh, central part of Urumieh–Dokhtar magmatic arc)

The Rangraz copper deposit is located in 18 km of northern Saveh which is in the central part of the Uromieh–Dokhtar magmatic arc. The host rocks are mainly volcanics and volcaniclastics of Eocene which altered and mineralized by intruding the quartz monzodiorite intrusion and andesitic-basaltic dikes in them. Hydrothermal alterations are propylitic, sericitization, silicification, and the chlorite-clay minerals-quartz assemblage. The principal hypogene ore minerals include pyrite, chalcopyrite, bornite, specular hematite, and magnetite. The Rangraz quartz monzodiorite composes of plagioclase, K-feldspar, quartz, fine grain biotite and amphibole shows granular to porphyritic textures. These rocks are commonly metaluminous and calc-alkaline. The high CaO (2.61 to 5.81) and Na2O (6.90 to 7.78) and low K2O(0.04 to 0.38), Fe2O3 (2.60 to 4.58), and MgO(1.22 to 2.81) contents can be caused by the extensive propylitic alteration in intrusion rocks of the study area. According to the tectonic setting discrimination diagrams, and trace and rare earth elements distribution patterns, depletion of Ti, P and LREE enrichment are the subduction at active continental margin tectonic characteristics. Significant negative Eu anomalies and relative depletion in Sr indicate the presence of plagioclase as a stable phase at magmatic source. The result of petrogenetic studies represent that crystal fractionation, and magma mixing were the most dominant processes controlling magmatic evolution.