江西新余良山钼矿氢-氧-硫-铅同位素特征及指示意义

在前人研究成果的基础上，对江西新余良山钼矿床的地质特征进行了详细研究，系统测试了矿床中石英脉型钼矿石样品的氢、氧、硫和铅同位素组成，进而探讨钼矿床的成矿流体性质以及成矿物质来源。良山钼矿床δD值变化范围-61‰~ -57.9‰，平均值-59.1‰；δ18O_V-SMOW值变化于7.1‰~10.5‰，平均值9.2‰，流体的δ18O_H2O值变化于-3.32‰~-0.52‰，平均值-1.52‰，表明成矿流体具有岩浆水和大气降水混合流体特征。硫化物的δ34S_V-CDT值为-1.8‰~2.6‰，极差4.4‰，平均值1.12‰，其中黄铁矿δ34S_V-CDT值为-1.8‰~2.6‰，辉钼矿δ34S_V-CDT值为0.8‰~2.3‰，硫同位素表现为较小的正值特征，具有典型的岩浆硫组成特点。良山钼矿石中的矿石铅同位素206Pb/204Pb值为17.555~19.474，207Pb/204Pb值15.486~15.768，208Pb/204Pb值37.942~39.943，μ值9.35~9.7，ω值37.06~38.31，Th/U值3.8~3.96，矿石铅为混合铅，表明成矿物质为混合来源。良山钼矿床应为岩浆热液型-石英脉型钼矿床，是中生代华南板块板内构造演化区域金属成矿作用大爆发的产物。 

H-O-S-Pb ISOTOPIC COMPONENTS OF THE LIANGSHAN MOLYBDENUM DEPOSIT IN XINYU, JIANGXI PROVINCE AND THEIR IMPLICATIONS FOR THE ORE FORMING PROCESS

On the basis of predecessors' research results, We study the geological characteristics of the Liangshan molybdenum deposit in Jiangxi province and test H-O-S-Pb isotopic components of the molybdenum stone samples in quartz vein systematically, and then discusse the metallogenic fluid properties as well as the source of ore-forming materials of the molybdenum deposit. The δD of the ore-forming fluids are between -61‰~-57.9‰, with the average of -59.1‰; and the δ18O_V-SMOW of the ore-forming fluid are between 7.1‰~10.5‰, with the average of 9.2‰; and the δ18O_H2O of the ore-foring fluids are between -3.32‰~-0.52‰, with the average of -1.52‰, which indicate that the ore-forming fluid has the characteristics of magmatic water and meteoric water mixed fluid. The δ34S_V-CDT of the sulfide mineral are between -1.8‰~2.6‰, with the range of 4.4‰ and the average of 1.12‰, of which the δ34S_V-CDT of the pyrite are between -1.8‰~2.6‰ and the δ34S_V-CDT of the molybdenite are between 0.8‰~2.3‰. The sulfur isotope values are smaller positive which show the characteristics of typical magmatic sulfur. The values of 206Pb/204Pb of the ore samples are between 17.555~19.474, and the values of 207Pb/204Pb are between 15.486~ 15.768, as well as the values of 208Pb/204Pb are between 37.942~39.943, with the μ values of 9.35~9.7 and the ω values of 37.06~38.31, as well as the Th/U values of 3.8~3.96, which indicate the ore are rich in mixed lead, and the ore-forming material sources are mixed. The Liangshan molybdenum ore should belong to the magmatic hydrothermal type and quartz vein type deposit, which is a product of the metal mineralization outbreak during the intraplate tectonic evolution of south China plate in Mesozoic.