Metamorphic Evolution of the Garnet Amphibolite Schist from Mawat Ophiolite, Kurdistan Region, Northeast Iraq: Geochemistry, Mineral Chemistry and Thermodynamic Approach

The garnet amphibolite schist is associated with the gabbroic unit of Mawat ophiolite, Kurdistan region, Northeast Iraq, in imbricated zone Zagros orogenic belt. Field observation, petrographic study, mineral chemistry, geochemical data, and thermodynamic modeling were used to demonstrate identification, predict observed stable assemblages, validate protolith. assemblages prograde are (pyrope-almandine), chlorite (clinochlore), amphibole (grunerite), plagioclase (anorthite), iron oxides while (almandine-pyrope), (chamosite), (cummingtonite), oxide represent retrograde assemblage. relict pod metagabbro center body consists mainly plagioclase, amphibole, pyroxene, oxide. Geochemical data reveals that rock depleted SiO2 CaO enriched refractory elements compared metagabbro. This may be attributed generation silicic melts by partial melting producing nearby plagiogranite. rare earth (REE) patterns show light (LREE) gradually heavy (HREE). Thermodynamic modeling, field combined study constrains two metamorphic stages one possible anticlockwise P-T-t path for schist, increasing pressure temperature rocks units ophiolite. reached peak conditions at more than 800 °C 8–10 kbar, which partially melted produced resitite melt. Later, retrograded lower stage temperatures ranging from 620 650 pressures 6.5 6.8 kbar. Anticlockwise paths suggested based on Moreover, gabbro considered protolith have been undergone eclogite facies metamorphism later overprinted facies.