Thermobarometery of the Sarvian intrusion in NE of Delijan based on mineral chemistry of amphibole and plagioclase

Sarvian intrusion is located in northeast of Delijan in the Orumieh-Dokhtar magmatic belt. Sarvian pluton consists of acidic and intermediate units and is composed of granite, granodiorite, tonalite and quartz-diorite. Main minerals of the intrusion are plagioclase, amphibole, biotite, quartz and K-feldspar. In this research, based on the EPMA analyses, thermobarometry of the rocks investigated. Based on microprobe analysis, the amphibole is in calcic amphibole group and its composition varies from magnesiohornblende to actinolitehornblende. The plagioclase composition is also in the range of andesine to labradorite. The average crystallization pressure of amphibole inclusions, quartz-diorite and tonalite are estimated 2.6, 1.56 and 1.4 Kbar respectively, using aluminum in hornblende barometer. The average equilibrium temperatures are 875.2, 795 and 759.7 ºC respectively. The intrusion is formed in high oxygen fugacity condition and Log ƒO2 is estimated to be about -11.06 to -15.76.