Tectonomagmatic development of the Eocene Pasevh pluton (NW Iran): Implications for the Arabia-Eurasia collision

摘要: Abstract The Pasveh pluton is one of a number intrusive complexes in the northwestern part Sanandaj-Sirjan Zone (SSZ), NW Iran. major this complex composed high-K, calc-alkaline granitic rocks. geochemical data indicate that rocks, although compositionally similar, are not cogenetic and can be divided into three groups. first group (mesocratic granitoids) represented by largest outcrop pluton. It mainly metaluminous magnesian monzodiorite to granodiorite with abundant MME gabbroic enclaves. Zircon LA–ICP–MS U–Pb dating yielded Eocene crystallization ages (ca. 40 Ma) for group. (eNdt = +2.0 +2.5), +1.5 +1.6), enclave +3.3 +4.7) have distinct Nd isotopic compositions. second (39.7 ± 0.6 Ma), weakly peraluminous monzogranites Carboniferous Cretaceous inherited zircons. Leucocratic dikes adakitic composition comprise third silicic slightly younger (37.5 ± 0.3 Ma) than host rocks cross-cut mesocratic granitoids. Our results underplating basaltic magmas related extensional stress overlying Iranian plate during induced partial melting lower crust. Differences amount source likely responsible volume heterogeneity their melt Subsequent generation, it possible mixed mafic variable proportions produce hybridized intrusion leucogranite after emplacement suggests or Neo-Tethys subduction there was another period magmatism subducted slab.