نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه زمین شناسی، دانشگاه پیام نور، تهران ، ایران
2 گروه زمین شناسی، دانشگاه پیام نور ، تهران، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The studied magmatic units are located 48 kilometers north of Shahrekord and near the village of Shorab in the middle part of the Sanandaj-Sirjan structural zone. The lithological units of the region include Cretaceous sedimentary units (lime carbonates and dolomite), shales and sandstones (Jurassic), and mafic to intermediate igneous rock complexes. The composition of the igneous rocks mainly includes andesite, basaltic andesite, basalt, gabbro, and diorite units with the main mineral complexes of olivine, pyroxene, plagioclase, amphibole, and biotite along with minor minerals of apatite, sphene, and opac, and secondary minerals of calcite, epidote, and chlorite. The dominant texture of the studied volcanic samples is mainly porphyry and microlithic porphyry, glomeroporphyritic and hyaloporphyritic, and the dominant texture of the internal igneous samples is medium to coarse-grained granular. Chemical analysis of the brine igneous samples confirms the calc-alkaline nature of these samples. This igneous complex was formed in a subduction tectonic setting. In the pattern of rare earth element changes, these samples have enrichment of light rare earth elements relative to heavy rare earth elements and have negative anomalies of Ti, Zr and positive anomalies of Sr and Pb, which indicate the characteristics of a continental arc and an active continental margin. Geochemical data integration indicates that the magma source forming the Shorab volcanic rocks was isolated at a depth of approximately 100 km from a garnet lherzolite mantle source and then underwent crustal contamination during ascent.
کلیدواژهها [English]
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