SHRIMP zircon U-Pb age and geochemical characteristics of Qinglung granodiorite in Baingoin area, Tibet

Located in the middle of Baingoin-Nujiang suture zone，the Qinglung rock mass is an important component part of the Baingoin-Lhari magmatic zone. The rock mass is composed mainly of granodiorite formed in Early Cretaceous. Zircon SHRIMP U-Pb age is 123.1±3.4 Ma，which reflects the age of pluton emplacement or crystallization. Geochemical data indicate that the rock mass has high SiO2 content and relatively low K2O/Na2O ratios, belonging to weakly peraluminous rocks. Qinglung rock mass is enriched in HREE and depleted in LREE，with relatively weak negative Eu anomaly. In the trace element spider diagram, granodiorite shows strong negative Nb, Ta, Ti and Y anomalies， similar to the island arc granite in geochemical characteristics. The tectonic setting of Qinglung rock mass was a subduction environment, mainly formed by the melting of the subduction slab.