Ore-Forming Fluid and Thermochemical Sulfate Reduction in the Wusihe Lead-Zinc Deposit,Sichuan Province,China
Xiong Suofei
Yao Shuzhen
Gong Yongjun
Tan Mantang
Zeng Guoping
Wang Wei
Abstract：The Wusihe lead-zinc deposit,hosted in the Dengying Formation,is a large lead-zinc deposit in the Sichuan Province, China.The previous research noted the Wusihe deposit was classified as a sediment-hosted stratiform lead-zinc deposit.Howev-er,our field survey result suggests that hydrothermal ore-forming processes are crucial to lead-zinc mineralization.In this pa-per,we present a detailed petrographic,microthermometric and laser Raman spectroscopy study of fluid inclusions from the Wusihe deposit reveals the characteristics of ore-forming fluids and mineralization mechanism.Primary fluid inclusions (FIs)in dolomite,quartz,calcite,fluorite and sphalerite are mainly two phases (L+V type).Microthermometric data show the hom-ogenization temperatures range from 120 ℃ to 260 ℃,and the average of salinity is 10.0% NaCl eqv.The estimated trapping pressures are 32 MPa to 68 MPa.The laser Raman spectroscopy shows that the gas components have a certain amount of CH 4 , H 2 S,C2 H 6 ,C2 H 2 ,N2 and NH 3 .The mixed ore-forming fluids offer heat,SO 4 2- ,and Mg2+ to provoke the thermochemical sulfate reduction (TSR).The TSR could be a key factor for sulfur source and H + .The change of pH value leads to the precipi-tation of metallogenic elements.
Keywords：ore-forming fluidfluid inclusionslead-zinc depositthermochemical sulfate reductiongeochemistry
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：16( 105-120 )