Abstract: The Bilihe gold deposit, located in the Bainaimiao arc along the northern margin of the North China Craton (NCC), is considered a porphyry mineralization system. This study is focused on the LA-ICP-MS U-Pb geochronology and Lu-Hf isotopic composition of zircons from the causative granodiorite. The results show that geochemical features, such as peraluminous high-K calc-alkaline characteristics, SiO2 content (61.3%64.4%), ratios of K2O/Na2O (0.520.87) and A/CNK (0.820.95), enrichment of LILEs (eg. Rb, U, Th) and LREEs, depletion of HFSEs (eg. Nb, Ta, Ti) and HREEs, and negative Eu anomalies (δEu=0.501.03), indicate the Bilihe granodiorite is similar to typical arc-related granitoids. Also, two granodiorite samples (zk086-53 and zkI005-105) had similar zircon ages and Lu-Hf isotopic characteristics, with weighted mean 206Pb/238U ages of 268.1±1.8 Ma (MSWD=1.17, 1σ) and 267.7±4.1 Ma (MSWD=1.06, 1σ), respectively,  εHf(t) values of 3.28.7 and -0.68.3, respectively, and TDM2 ages of 1085737 Ma and 1330762 Ma, respectively, suggesting that the Bilihe causative granodiorite likely formed during the EarlyMiddle Permian, from the underplating magma of partially molten juvenile crust mixed with partially molten ancient basement rocks in a continental arc setting.
Key words: Central Asian orogenic belt; Solonker zone; Bilihe gold deposit; zircon U-Pb ages; Lu-Hf isotopes

Key words: Central Asian orogenic belt, Solonker zone, Bilihe gold deposit, zircon U-Pb ages, Lu-Hf isotopes