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江苏观山铜铅金矿是典型的高硫型浅成低温热液矿床。本文通过对观山铜铅金矿床氢、氧、碳、硫同位素组成的研究,探讨成矿溶液中水、碳、硫的来源以及成矿溶液的演化。同位素测定显示石英流体包裹体水的δD=-90‰～-70‰,δ18O水=-8.9‰～-1.1‰;热液方解石流体包裹体水的δD=-90‰～-81‰,δ18O水=0.1‰～2.3‰。氢氧同位素组成说明成矿流体主要为与围岩进行过水岩反应的循环大气降水,不排除有少量岩浆水的加入。黄铁矿与黄铜矿矿石的δ34SV-CDT=5.8‰～9.9‰,平均值为7.6‰,表明该矿成矿过程中的S很可能是沉积岩来源的硫与岩浆岩来源硫的混合。矿床中可见较多的重晶石等硫酸盐矿物,这种高价态硫的矿物的存在显示其成矿溶液具有富集34S的特征,加上成矿过程中流体的沸腾导致H2S等气体大量逸出和残余岩浆流体富集34S,使得沉淀的黄铁矿、黄铜矿等硫化物同样具有富集34S的特征;热液方解石碳同位素δ13C方解石=-4.1‰～6.1‰,平均为δ13C方解石=1.3‰,显示其中的C主要来源于流体对流循环过程中对基底岩石中碳酸盐地层的溶解。
Jiangsu Guanshan copper-lead gold mine is a typical high-sulfur epithermal deposits. In this paper, the study on the isotopic compositions of hydrogen, oxygen, carbon and sulfur in the Gunshan Cu-Pb-Au deposit explores the sources of water, carbon and sulfur and the evolution of ore-forming solutions in ore-forming solutions. Isotope determination shows that δD = -90 ‰ ~ -70 ‰ and δ18O water = -8.9 ‰ ~ -1.1 ‰ of quartz fluid inclusions; δD = -90 ‰ ~ -81 ‰ of hydrothermal calcite fluid inclusions, δ18O water = 0.1 ‰ ~ 2.3 ‰. The composition of hydrogen and oxygen isotopes indicates that the ore-forming fluid is mainly cyclic atmospheric precipitation that has been subjected to water-rock reaction with the surrounding rock and does not exclude the addition of a small amount of magmatic water. Δ34SV-CDT of pyrite and chalcopyrite ore is 5.8 ‰ ~ 9.9 ‰ with an average of 7.6 ‰, indicating that S in the ore-forming process of the ore is likely to be a mixture of sedimentary-derived sulfur and magmatic-derived sulfur. There are many sulphate minerals such as barite in the deposit. The existence of this high-value sulfur ore shows that the ore-forming solution has the feature of enrichment of 34S, and the boiling of the fluid in the ore-forming process leads to a large amount of gas such as H2S The enriched 34S is enriched in the precipitated pyrite, chalcopyrite and other sulfides. The hydrothermal calcite carbon isotope δ13C calcite = -4.1 ‰ ~ 6.1 ‰, averaging δ13C calcite = 1.3 ‰, showing that C mainly comes from the dissolution of carbonate rocks in the basement rock during the convection circulation.