Application of mineral chemistry in determination of protolith and thermobarometry of the Sartip Abad metamorphic rocks (Qorveh-Kurdistan Province)

The Sartip Abad metamorphic complex in Qorveh (Kurdistan Province) is located in the Sanandaj-Sirjan zone. The complex is composed of regional metamorphic rocks including contact metamorphic rocks (hornfels), variety of schists (amphibole schist, actinolite schist, mica schist, and garnet schist), marble, metadiorite, metagabbro, and paragneiss. In schists and paragneiss, biotite is siderophilite and in hornfels and metadiorite is anite to phlogopite in composition, respectively. Paragneiss and metadiorites include hornblende and actinolite. The garnets, in the garnet-mica schist, are almandine type, and plagioclase crystals in the metadiorites and metagabbros are labradorite type in composition, as well as their paragneiss have andesine- type plagioclase. Petrography and thermobarometric studies indicate that the different types of regional metamorphic rocks are formed in green schist to epidote-amphibolite facies and in the interval between biotite and staurolite zones. But for contact metamorphic rocks, the maximum facies is assumed albite-epidote hornfels in isograd of zoisite to amphibole. Thermometry calculations, using biotite single and garnet-biotite exchange, show that the average temperature for the metamorphic rocks of this region is about 567°C and for the contact metamorphic rocks is about 647 °C. Also, we used thermo-barometer methods for M1 and M2 metamorphic stages. Data are yielded, M1 stage temperature and pressure are about 578°C and 5.16 kb and for M2 stage ~565 °C and 4.6 kbar. Based on field relationships, petrographic evidence and geochemical data, protoliths are sedimentary rocks including greywackes/arkoses and shales for paragneiss, hornfels and schists, respectively.