Petrology and Mineral Chemistry of peridotites of the Faryab Ophiolitic Complex, Golashkard region-southeast of Sanandaj-Sirjan zone

The Faryab ophiolitic complex is located in Golashkard region, in the southeastern part of Sanandaj-Sirjan zone. This complex is mainly composed of the ophiolitic mantle part consisting of dunite, wehrlite, and pyroxenite, as well as chromitite and serpentinite, which was thrusted on the metamorphic rocks of the Bajgan complex. Dunites are found in the form of bodies sometimes containing thin layers of chromitite. Wehrlite and pyroxenite are also exposed as minor dykes in different parts of the complex. The main texture in the wehrlite and dunite is granular and cataclastics. The chromitites appear in both stratiform and podiform. Microscopic evidence indicates that the presence of lattice preferred orientation in minerals may be formed during recrystallization at high- temperature mantle. The chemistry of minerals in the peridotites shows that rocks including forsterite with low chromium and high nickel, diopside and magnesium-bearing Cr-spinel with small amounts of orthopyroxene were partially melted in the upper mantle up to 35 to 40%. Using tectonic setting discrimination diagrams led us to conclude that the Faryab complex peridotites are a part of the oceanic lithosphere which have emplaced in the supra-subduction zone, suffered partial melting evolutions and then tectonically emplaced in the crust in the form of ophiolitic remnants.