Genesis of the Longkou–Tudui gold deposit, Jiaodong Peninsula, eastern China: Constraints from zircon U-Pb dating, fluid inclusion studies and C–H–O–S stable isotopes

•Gold mineralization of the Longkou–Tudui deposit occurred in the early Cretaceous.•Magmatic rocks in this ore field have no genetical association with gold mineralization.•This deposit has a heavy sulfur source inherited from the Jingshan Group.•Fluid cooling and dilution processes were crucial to the gold mineralization.•The genesis of Longkou–Tudui gold deposit is similar to other Jiaodong gold deposits.