Zircon U-Pb Age and Geochemistry of Yamusi Granodiorite in the Eastern Part of the Qilian Orogen, China

Yamusi granodiorite in the eastern part of Qilian Orogen consists mainly gneissic granodiorite. Researchers have studied other nearby rock masses, and many studies, such as those focusing on zircon U-Pb age chronology geochemistry granodiorite, still need to be completed. We obtained a new LA–ICP–MS 480.3 ± 1.3 Ma for which suggested that it was formed during early Ordovician period. The whole-rock geochemical data show this is relatively rich Na poor K (K2O/Na2O = 0.40–0.73). metaluminous–weakly peraluminous can classified medium-K calc-alkaline granite. It yields high Sr/Y ratios (35.17–53.78) low Yb (<18 ppm) Y (1.8 contents, an Mg# value <45, La/Y (2.9–13.4, mean 5.76). trace element compositions are characterized by positive large-ion lithophile elements (LILEs; e.g., Cs, Rb, Ba) negative high-field-strength (HFSE; Nb, Ta, Ti) anomalies, similar arc magmatic rocks. There clear fractionation between light heavy rare earth (REEs), with (La/Yb)N 1.77–9.03 (mean 3.88). petrogenesis research suggests originated from partial melting mafic lower crust, minor mantle-derived component. Based regional geological setting, we suggest northward subduction Proto-Tethyan oceanic crust form intracontinental arc.