Abstract:Shanhou gold deposit is a large scale gold deposit, locating in the southern part of Zhaoyuan Pingdu gold mineralization belt. On the basis of detailed mineralogical observation and microstructure study of pyrite, isotopic composition of quartz H O, gold bearing pyrite Sr Nd Pb, He Ar in main mineralization stage (the second and third stages) of Shanhou gold deposit have been analyzed systematically. As showed by the test results, the fluid inclusions in the gold bearing pyrite in Shanhou gold deposit are 0.45～1.15Ra (Ra is the value of air), and contain a certain amount of crust radioactive η40Ar. The ore forming fluid shows the characteristics of crust mantle mixed fluid. The H O isotope composition also indicates that the ore forming fluid may have come from enriched mantle fluids. The Ar value of 40Ar/36Ar ranges from 679.32 to 804.23, which is 2~3 times the characteristic value of atmospheric saturated water, and is similar to the characteristic value of 40Ar/36Ar derived from enriched mantle samples in northeastern China. The H O and He Ar isotopic compositions also indicate that the ore forming fluid may come from enriched mantle fluid. The analysis results of Sr Nd and Pb isotopic compositions indicate that the ore forming materials may mainly come from Linglong granite and Guojialing granite. Accompanying with Cretaceous extensional activity and large scale magmatic activity in Jiaodong area, the multi stage granite body formed intruded and replaced the Jiaodong rock group. In summary, the ore forming fluid of Shanhou gold deposit is crust mantle mixed fluid, which mixed with atmospheric precipitation in the late stage of mineralization. The ore forming materials are mainly from Linglong granite, Guojialing granite and Precambrian metamorphic basement.
