Petrology and Geochemistry of Shah Ashan Dagh Mafic Rocks and A-type Granite in NE of Khoy, NW Iran

The study area as a part of Maku-Tabriz zone is located in about 20 km NE of Khoy, NW Iran. Shah Ashan Dagh granite covers about 60 km2 of the area and emplaced into Permian host rocks and covered by Oligo-Miocene sedimentary rocks (Qom Formation). The Shah Ashan Dagh intrusive rocks composed of gabbro and alkali-feldspar granite. Porphyric and granophyric textures indicate shallow depth emplacement and perthitic texture shows hypersolvous nature of this body. The studied mafic rocks have high LREEs relative to HREEs and they indicate relatively enrichment of LILEs and depletion in HFSEs (exception Hf, Ta, Nb). The studied mafic rocks based on positive Nb and Ta anomalies show similarity to plum type MORB. These rocks are tholeiitic and they have mantle plum enriched source. Shah Ashan Dagh granite characterized with high-K, sub-alkaline, metaluminous to peraluminous and weakly peralkaline nature. They have high content of LILEs, especially Th and Rb, and low content of Eu, Sr, Ta, Nb, Ba, and Ti, implying the granites may have been derived from crustal melts.