نویسندگان
استادیار گروه زمینشناسی، دانشگاه پیامنور، تهران، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Mokhtaran Volcanic cones are located in the northern part of the Sistan suture zone - southwest of Birjand, as several distinct and scattered structures. The complex includes some individual cones with the composition of basaltic andesite, andesite, and trachyandesite located on Paleogene flysch deposits of the plain. The main phenocrysts of these rocks are plagioclase, pyroxene, and hornblende in lower amounts and porphyritic and glomeroporphyritic as their common textures. Their mesostasis is generally glassy to microcrystalline and biotite, olivine, and opaque are secondary phases. Geochemical investigations indicate the calc-alkaline nature of these rocks, which were formed in a post-collision volcanic arc tectonic setting. The distribution pattern of REE indicates the enrichment and depletion for LREE and HREE respectively, and their main characteristic feature is the negative anomaly of Nb and positive for Pb. Based on tectonic setting diagrams, Mokhtaran Plain samples belong to the post-collision volcanic arcs related to the active continental margins concerning subduction.
کلیدواژهها [English]
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