Genesis of the early mesozoic granitoids at the Hardat Tolgoi Ag-Pb-Zn deposit in East Ujimqin Banner, Inner Mongolia, NE China: Insights from whole-rock geochemistry, zircon U-Pb-Hf isotopes, and Pb-Si systematics

•LA − ICP − MS zircon U-Pb geochronology shows that granitic intrusions in Hardat Tolgoi were emplaced at the Early Jurassic.•These high-K calc-alkaline granitoids were generated by partial melting of the juvenile lower crust.•The magmatism at Hardat Tolgoi was probably attributed to the southeastward subduction of Mongol − Okhotsk oceanic plate beneath the Erguna massif, with exsolved magmatic fluids favorable to the Ag-Pb-Zn mineralization.