LA-ICP-MS Zircon U-Pb Age,Geochemistry of the Wuleiku-Kelang Pluton from the Dadonggou Area of Altay in Xinjiang and Its Tectonic Implications

LA-ICP-MS zircon U-Pb ages and whole rock geochemical data about the Wuleiku-Kelang pluton from the Dadonggou area of Altay in Xinjiang have been reported in this paper.Zircons from granodiorite and syenogranite have well-defined oscillatory zoning, which yielded the mean ²⁰⁶Pb/²³⁸U ages of (404±2.7)Ma (MSWD=0.24) and (410.5±2.1)Ma (MSWD=0.3), respectively, indicating that the Kangbutiebao Formation was formed prior to 410Ma.The granitoid rocks have high SiO₂ (ranging from 72.22% to 78.33%), total alkali (Na₂O+K₂O) (changing from 5.76% to 9.24%) and Al₂O₃ (varying from 12.07% to 14.30%), and low P₂O₅ (ranging from 0.02% to 0.1%) and MgO+FeO (changing from 0.33% to 3.50%).In addition, they are characterized by high A/CNK values (varying from 1.04 to 1.47) and low CaO/Na₂O ratios (average ratios are less than 0.3), which have been defined as calc-alkaline peraluminious granitoid rocks.These rocks have obvious negative anomalies of Ba, Sr, P, Ti, Nb,Ta and Eu (δEu=0.05~0.67) and obvious enrichment of LREE, Rb, Th, U and K, resembling that these granitoid rocks were formed in the volcano arc settings.Combined with the tectonic evolution of the southern margin of Altay, it's suggested that these granitoid rocks were generated by partial melting of the crust in an active continental margin, with the residues of plagioclase, ilmenite and apatite.