Petrogenesis of Mo-associated Mesozoic granitoids on the Jiaodong Peninsula: Implications for crustal architecture and Mo mineralization along the Dabie–Sulu Orogen

Abstract

Recent studies have demonstrated a linkage between the crustal architecture and the location of magmatic–hydrothermal Cu deposits in collisional orogens. However, if and how the crustal architecture controls the distribution of magmatic–hydrothermal Mo deposits in collisional orogens is unclear. Here, we present zircon U–Pb dating, geochemical and Sr–Nd–Hf–O isotopic data for granitoids associated with Mesozoic Mo mineralization on the Jiaodong Peninsula which exhibits substantial endowment differences to the Dabie Orogen. Geochronology data show that the Mo-associated granitoids occurred at ca. 160 Ma and 117 Ma. The Jurassic Mo-associated monzogranite was derived from melting of the thickened North China Block lower crust in a subduction-related setting. The Early Cretaceous Mo-associated granodiorite and granite were originated from a modified North China Block thorough crust–mantle interactions, induced by rollback of the Paleo-Pacific Plate. Our results complemented by published data indicate a crustal architecture characterized by South China Block gneisses overlying North China Block lower crust in the Sulu Orogen and wedging into the North China Block in the Jiaobei Terrane. By comparing the Mo–associated granitoids in Dabie Orogen and Jiaodong Peninsula, we conclude that magma source differences controlled by crustal architectures lead to Mo endowment diversities along the Dabie–Sulu Orogen.