نوع مقاله : مقاله پژوهشی
نویسندگان
1 عضو هیئت علمی گروه زمین شناسی دانشگاه ارومیه
2 گروه زمین شناسی دانشگاه شهید چمران اهواز
3 گروه زمین شناسی دانشکده علوم زمین دانشگاه شهید چمران اهواز
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The fallen pieces of garnet-biotite-kyanite schists from the Qori regional metamorphic complex, Neyriz area, the southern part of the Sanandaj-Sirjan zone, with an age of about 187 Ma, into the Chah-Bazargan leucodiorite intrusions led to the pieces underwent high-grade contact metamorphic conditions and converted into migmatitic xenoliths at 173 Ma. Parts of the produced melts were accumulated, resulting in the creation of granitic pods and patches within the intrusions. Petrographic evidence revealed that equilibrium assemblage spinel + garnet + perthitic feldspar + cordierite + silimanite formed at the peak of metamorphism in the xenoliths. The calculated phase diagram show that anatexis in the xenoliths would occur at 700 to 750 °C and <5 kbar in presence of sufficient H2O. However, chemical compositions of garnet and biotite grains and calculated isopleths based on the minerals show that anatexis could be onset in some lower temperatures. The T-XCO2, T-XO2, and T-XMg diagrams demonstrate that increasing in contents of CO2 and O2 and Fe/Mg ratio of the protolith can decrease temperature of partial melting onset.
کلیدواژهها [English]
)