湖南花垣铅锌矿床成矿物质来源与成矿机制——来自S、Pb、Sr同位素的证据

发布时间：2019-04-04 15:54

【摘要】：湖南花垣铅锌矿床位于扬子地台东南缘,是湘西—黔东地区最典型的超大型铅锌矿床,已探明铅锌储量超过500×10~4t,其预测资源量逾1800×104t。报道了该矿床主要矿石硫化物的S、)Pb同位素研究成果,结合前人的Sr同位素数据,分析了矿床的成矿物质来源,并探讨了成矿机制。硫化物的δ~(34)S值变化范围较小,为24.5‰~34.7‰,平均值为30.2‰,硫来源于各时代碳酸盐地层中硫酸盐热化学还原作用(TSR),有机质在还原反应过程中发挥了重要作用;硫化物的~(206))Pb/~(204))Pb、~(207)Pb/~(204)Pb、~(208)Pb/~(204)Pb值分别为18.139~18.678、15.691~15.832、38.300~39.255,变化范围较小,具有上地壳来源的特点,赋矿地层下部具有高)Pb-Zn含量的地层为成矿提供了大量的金属物质;闪锌矿的~(87)Sr/~(86)Sr值变化范围为0.70915~0.70996,高于赋矿地层清虚洞组灰岩的Sr同位素比值(0.70885~0.70909),表明成矿流体可能流经围岩及基底地层,从而引起Sr同位素比值因混染作用而升高;矿石矿物的沉淀机制为2种流体的混合,即含金属物质的成矿溶液与富含有机质、硫酸盐的热水溶液在合适的部位汇合,并发生反应。
[Abstract]:Huayuan lead-zinc deposit in Hunan Province, located in the southeast margin of Yangtze platform, is the most typical super-large-scale Pb-Zn deposit in western Hunan and eastern Guizhou. It has been proved that the reserves of lead and zinc exceed 500 脳 10 ~ 4 t, and its predicted resource amount exceeds 1800 脳 10 ~ 4 t. This paper reports the research results of S,) Pb isotopes of the main ore sulphides in this deposit. Combining with the Sr isotopic data of predecessors, the ore-forming material sources of the ore deposits are analyzed, and the ore-forming mechanism is discussed. The 未 ~ (34) S values of sulphide vary little, ranging from 24.5 鈥，

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