Geochemistry of Trace Elements and REEs in the Dihu Cu-Au Polymetallic Deposit,Congjiang,Guizhou Province

Industrial ore bodies of the Dihu Cu-Au polymetallic deposit,Congjiang Count,Guizhou province,are produced in the northeast limb of the Jiache nose-like anticline and hosted in the low-grade metamorphic sedimentary rock of the Jialu Formation,the Neoproterozoic Xiajiang Group.Correlation analyses reveal a correlation between Mo-Ga-Cd-As-Co-In and Cu-Pb-Zn-Ag,suggesting that they are good tracers.Cluster analyses show correlation of Mo and Cu,implicating that Mo is potential ore-forming metal in the mining district.The ratios Co/Ni of pyrite are 3.17to 26.5,similar to those of hydrothermal genesis pyrites.The Y/Ho ratios of pyrite(23.4-33.6)are similar to those of wall rocks(26.2-31.6),suggesting that the ore-forming metals derived from the host rocks.All samples enrich LREEs,and have negative Eu and weak Ce anomaly.Similar chondrite-normalized REE patterns of the hydrothermal pyrite,quartz and host rock indicate that their REE were inherited from the host rocks.We believe that the ore forming fluids and metals are partially derived from the host rocks.