نوع مقاله : مقاله پژوهشی
نویسندگان
1 عضو هیات علمی دانشگاه هرمزگان
2 مدرس دانشگاه
3 عضو هیئت علمی دانشگاه هرمزگان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
The Dahbid rhyolites in the southern Sanandaj–Sirjan Zone occur as small intrusive bodies with a subalkaline composition, high silica, low TiO2, Fe2O3t, and MgO, high differentiation index, and normative corundum >1%, reflecting a peraluminous S-type granite affinity. The presence of biotite, muscovite, sphene, apatite, and zircon together with low Nb/Ta and Zr/Hf ratios confirms a crustal magma source. Variations of Th and Th/U indicate an intermediate position between S- and I-type granites and partial melting of the middle to lower continental crust. REE patterns show LREE enrichment, lack of strong HREE depletion, and pronounced negative Eu anomalies, suggesting residual plagioclase in the source. Zircon saturation index indicates low melting temperatures (<800 °C) and pressures (<300 MPa) for sedimentary protoliths. These features resemble low-temperature peraluminous granites in high-pressure post-collisional orogens and represent crustal melting in a thickened continental setting.
کلیدواژهها [English]
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