نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه زمین شناسی، دانشکده علوم زمین، دانشگاه شهید بهشتی، تهران، ایران
2 گروه زمین شناسی، دانشگاه پیام نور، تهران، ایران
3 مؤسسه علوم زمینشناسی، آکادمی علوم لهستان، وروکلاو، لهستان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
The Qezeljeh-Kand volcano in northwest Iran hosts mafic enclaves that provide key evidence for mantle metasomatism related to the Neotethyan subduction. These enclaves, including phlogopite–pyroxenite, amphibole–phlogopite–pyroxenite, and olivine–phlogopite–pyroxenite, reveal a mafic mantle source modified by metasomatic processes. The presence of K-rich hydrous phases (phlogopite, amphibole), enrichment of LILE over HFSE, negative Nb–Ta anomalies, and LREE-enriched REE patterns are consistent with modal metasomatism, mainly fluid-induced by slab-derived agents. Sr–Nd isotopic data indicate an older, less-contaminated mantle source for the enclaves compared to their volcanic host. The comparison shows that enclaves chiefly record fluid-dominated modal metasomatism, whereas the host rocks reflect an additional contribution from melt-related metasomatism. These differences highlight the long-term role of subduction-derived fluids in the chemical modification of the lithospheric mantle beneath the area.
کلیدواژهها [English]
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