Abstract:The Lianzigou gold deposit is an integral part of the Jialu gold orefield in the Xiaoqinling region, with orebodies occurring mainly within highly metamorphic gneiss of the Qincanggou Formation of the Archaeozoic Taihua Group. The orebodies occur as veins and are controlled by the NEtrending structural fracture altered zone, with the trending direction parallel to NEtrending major faulting. On both sides of orebodies are the alteration zonation characterized by potassicsilicification, sericitizationsilicificationpyritization, chloritizationepidotization from core to the rim of the orebodies. The H and O isotopic compositions show that oreforming fluids comprised mainly mixture of magmatic water and meteoric water. HeAr isotope results demonstrate mixing feature of crustal and mantlederived components. The sulfur isotopic compositions in sulfides indicate that ores are characteristic of enrichment of light sulfur, which maybe result from sulfur isotope fractionation during the process of mineralization. The ore lead isotopic compositions are relatively homogeneous, suggesting a possible source of the Taihua Group (wallrock) for lead in ores. The H, O, S and Pb isotope compositions indicate the waterrock interaction during mineralization. The early K+rich alkaline oreforming fluid mixed with the shallow fluid and then fully reacted with the wall rock to exchange materials and energy through waterrock reaction, generating potassic alteration zone in the wall rock. With mineralization continuing, the oreforming hydrothermal fluids changed physicchemical conditions and carried Au to migrate in the forms of Au(HS)2- and Au(HTe)2-, finally resulting in precipitation and enrichment of gold in a more favorable environment.