REE Geochemical Characters of the Guocheng Gold Deposit,Eastern Shandong Province and Its Significance to Mineralizations

The Guocheng gold deposit,which is located in the northeastern margin of the Jiaolai Basin,with orebodies occurring in the Jingshan Group and ores predominately pyritized and pyrrhotitized,formed under more special geological conditions compared with other gold deposits in Jiaodong Peninsula. The REE analyses for Guocheng gold ore,Muniu mountains rock and mafic dikes were carried out using the method of ICP-MS and the source of ore-forming material and ore-forming fluid was discussed in this paper. The results show that REE Partition curves have two types,including rightist and flat type. The flat-type partition curve of ore is similar,in strong correlation,to that of granite,while the rightist-type partition curve of ore is analogous,in good correlation,to that of dikes. The late carbonated ore has high rare earth content. And there is an obvious negative Eu anomaly in ores except dikes. It indicates that the ore-forming materials are derived from Muniu mountains rock and deep crust,while the ore-forming fluid is derived from deep magma evolution. The formation of the orebody involves multi-stages.