Huangshaping lead and zinc metal deposits ore-forming mechanism and its prediction
|School||Central South University|
|Course||Mineral prospecting and exploration|
|Keywords||Huangshaping Metal deposit polygenetic compound deposit metallogenic prediction|
Huangshaping lead-zinc deposit is a large-scale oer deposit, which is needed to find new resource urgely because of long time mining. Therefor it has a great theory and practice significance for researching for mineralization mechemism and metallogenic prediction. From points of isotopic and trace elements compostion and their evolution features, ad based on the polygenetic metallogenic theory, the origin of mineralization material, ore deposit genetics, minerogenesis and location prediction of orebodies were thoroughly researched.The anomaly characteristics of regional structure, geochemistry, magnetogravity were concluded by comparing their features of Huangshaping, Shuikoushan, Dongpo, Yaogangxian and Xianghualing polymetal ore deposits.Based on the features of geology, magmatic rocks’ lithology and petrochemistry, trace elements and rare earth elements, the source and diagenesis mechanism of magmatc rocks and their evolution were deeply discussed from which the new understanding of multiple sources, polygenetics and multi-phase were gainedChecking the reason of change of carbon and oxigen isotope in barbonate by volatile action, mixing action rock-water exchanging action has comfirmed that there is an isotope exchanging in carbonate for rainwater + magma fluid and carbonate. The anomaly lead pattern with two stages can explain the isotope compostion by checking the patterns of two groups of normal lead, two stage anamaly lead formed short time and three stage anamaly lead. The two groups ofδ34SΣS values obtained by extrapolation confirmed that there sedimentary and magmatic origins for sulfur in hydrothermal solution.The researching on physical-gecchemical environment has shown that the skarn-formed temperature are 430℃～570℃; ore-formed pressure is 1000×105Pa: Xco2 is between 0.22～0.01, and the temperature of early stage skarn-formed fluid is more high and with high Xco2.With the temperature decreasing of the fluid and joining of H2O, which made temperature and Xco2 of later skarn-formed fluid down.The pressure in the stage of mineralization for sulphide are 0.9×105pa～300×105Pa, the salinity are 13.9～34wt（%） and temperature are 200℃～350℃.The migration forms of metal elements have been obtained by the temperature, oxgen fugacity sulfur fugacity pH value and salinity of mineralization stage, the migration forms of lead zinc and silver are mainly chlorine complex and hydroxyl complex and hydrogen sulfide complex in the first stage and HTe,HTeO3,H2TeO3 in the secondary stage.By synthetic analysis the geological features, mineralization conditions, metallogeny, ore-controlling factors, geochemical features and ore-forming process, it was suggested that formation of Huangshaping ore deposit underwent multiple phases of sedimentary mineralization, sedimentary and diagenesis mineralization phases in platform stage and magmatic fluid mineralization phase. Furhtermore, by integrating different location factors of the orebodies including magmatic intrusions, structures, strata, symbols of ore-hunting were summarized. Meanwhile, synthesis exploration works such as geological survey, structure geochemical and geophysical survey aimed to the target area were undertaken.