Geology and geochemistry of Mishu S-type granitoid NW Iran

The Mishu garnitoid complex, located NW of Mishu Mountains, southwest of Marand and northwest of Iran (East Azarbaidjan), and intruded into the metamorphosed Precambrian rocks (Kahar Formation). Based on petrographic studies, the pluton composed of acid rocks including granodiorite, monzogranite, syenogranite and two-mica granite, all cut by acid and diabasic dykes. The presence of surmicaeous xenoliths are evidences of refractory minerals and restite. Petrographic and geochemical studies indicate that the Mishu plutonic rocks can be classified as S-type granite having calc-alkaline and peraluminous nature. On chondrite and primitive mantle-normalized diagrams, almost all the rocks show enrichment in LILE and LREE, HREE, HFSE depletion as significant negative depletion in Nb, Ta, Eu, Ti, Sr and Ba, which is typical of calc-alkaline magmatism from subduction-zone environment. The geochemical data and position of the studied samples on discriminative tectonic diagrams show that the rocks are compatible with orogenic granitoids.