Abstract:Sanshandao gold deposit is one of the largest gold deposits in giant gold metallogenic provinces in Jiaodong area. In order to study its metallogenic age, by using sericite 40Ar/39Ar dating method, sericite crystallization age in the pyrite sericite quartzite of Sanshandao gold deposit has been determined. It is showed that the age of sericite 40Ar/39Ar is (118.35±1.21)Ma, and the age of anti isochron is (118.56±1.37)Ma. The mineralization age of Sanshandao gold deposit is (118.35±1.21)Ma. The zircon UPb age of Guojialing type granite is (127±2)Ma respectively, which is 9Ma different from gold mineralization age. Considering the slow cooling effect of magma emplacement in the deep intrusion is not more than 10Ma, it is considered that the mineralization event of Sanshandao gold deposit is closely related to surrounding rock of Guojialing granite intrusive event. Accompanying with the rise of rock mass and the decrease of the temperature, the gold rich multisource oreforming fluid enters the structural fracture system and strongly alters with the surrounding rocks, which further increases the mineral concentration of the orebearing hydrothermal fluid. In the process of the rise, the oreforming fluid is added with atmospheric precipitation, which accelerates the deposition of gold and forms a series of gold deposits.
