نوع مقاله : مقاله پژوهشی
نویسنده
گروه مهندسی معدن مرکز آموزش عالی شهید باکری میاندوآب-دانشگاه ارومیه، 5978159، میاندوآب، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسنده [English]
Intrusive rocks are exposed in southwest of Naqdeh in the Sanandaj-Sirjan zone, northwest Iran. There are mafic-intermediate appinitic rocks with calc-alkaline affinity. The accompanying granite is strongly evolved with the affinity of calc-alkaline and rich in potassium. The geochemical analysis of appinite and granitic rocks display LREE enrichment relative to HREE, enrichment of LILE elements, and negative Th and Nb anomalies. According to discrimination diagrams, appinite and granite rocks formed in the continental arc tectonic setting. The appinitic rocks have a lithospheric mantle with subducting slab fluids source. The granitic rocks have an asthenospheric-lithospheric mantle with metagreywaky continental crust contamination. We suggest that appinitic magma formed by roll-back of subducted Neo-Tethys oceanic lithosphere and granitic magma formed by breck-off the subducted Neo-Tethyan oceanic slab. The asthenospheric upwelling would also have provided enough heat for the partial melting of continental crust. It is possible that magma formed at a great depth and underwent a long period of fractional crystallization. Finally, evolved granitic rocks have been placed at a shallow depth of the crust.
کلیدواژهها [English]