SHRIMP U–Pb dating of zircon from two representative samples of the Bardkish syenitic pluton, Urumieh plutonic complex, northwestern Iran, yielded a Late Cretaceous weighted mean ²⁰⁶Pb/²³⁸U age of 91.1 ±0.8 Ma (Turonian). The pluton is characterized by high K₂O content, Ti–Nb–Ta depletion, enrichment in light rare earth elements and large ion lithophile elements compared to high field strength element, Mg‐rich biotite and calcic amphibole, suggesting a shoshonitic affinity. Geochemical features of the Bardkish syenite are consistent with derivation by fractional crystallization of initial mafic parent magmas. It is most likely that primary magma of the syenite originated from a metasomatized subcontinental lithospheric mantle source with minor crustal component, and underwent a fractional crystallization process during its emplacement. The estimates of trapping pressures and temperatures suggest that crystallization began at the middle crustal level (less than 11 km) near 700–730 °C. The generation of the Bardkish syenite could be related to the subduction of Neo‐Tethyan oceanic crust beneath the Central Iranian microcontinent and it possibly marks a major magmatic episode prior to the final closure of the Neo‐Tethyan ocean in northwest Iran.

中文翻译：

---

伊朗西北部Bardkish堇青石的年龄和地球化学：新特提斯俯冲期间的Senenite形成

从伊朗西北部的乌尔米耶克岩体复合体的两个Bardkish次生质岩体的代表性样品对锆石进行SHRIMP U‐Pb测年，得出白垩纪晚期加权平均²⁰⁶ Pb / ²³⁸ U年龄为91.1 ± 0.8 Ma（土耳其语）。插头的特点是K ₂高与HFSE，富含镁的黑云母和钙化角闪石相比，O含量，Ti-Nb-Ta耗竭，LREE和LILE中的富集，暗示了肖肖尼托亲和力。Bardkish堇青石的地球化学特征与初始镁铁质母岩浆的分步结晶衍生相一致。正弦岩的原生岩浆很可能起源于交变的次大陆岩石圈地幔源，地壳成分较小，并且在其沉积过程中经历了部分结晶过程。估计的捕集压力和温度表明，结晶是在700至730°C附近的中地壳水平（小于11 km）开始的。