نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشگاه تبریز
2 گروه زمین شناسی، دانشکده علوم طبیعی، دانشگاه تبریز
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
The Sari-Nou porphyry intrusive complex, of Oligo-Miocene age, is located in the Qaradagh volcanic–plutonic belt, NW Iran. These semi-deep plutonic bodies intruded into Eocene volcanic units. Their composition ranges from diorite to quartz monzonite, belonging to high-K calc-alkaline granitoids, mainly metaluminous, and of I-type affinity. The intrusions are crosscut by quartz monzonitic, microdioritic, dacitic, and trachydacitic dikes. Harker diagrams indicate magmatic differentiation; decreasing MgO, FeOt, CaO, TiO₂, P₂O₅ with increasing SiO₂ reflects crystallization of pyroxene, hornblende, and calcic plagioclase, while increasing Na₂O and K₂O suggests crystallization of sodic plagioclase and K-feldspar. Spider diagrams show LILE enrichment (Cs, Ba, Sr, Rb, Pb) and HFSE depletion (Nb, Ti, P, Zr). LREE are highly enriched with LaN/YbN ratios of 33–37. Geochemical evidence indicates emplacement in a post-collisional arc setting. Biotites from the potassic alteration zone are Mg-rich re-equilibrated types, with temperatures of 715–744 °C and ƒO₂ between 10⁻¹⁵·⁶ and 10⁻¹⁶·⁵ bars.
کلیدواژهها [English]
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