滇中前震旦纪地层内铅锌矿床硫、铅同位素特征及对成矿物质来源指示

发布时间：2018-07-10 06:42

  本文选题：硫同位素 + 铅同位素　； 参考：《地质与勘探》2017年02期

【摘要】：滇中前震旦系主要位于扬子地块西南缘,元谋-绿汁江断裂以东、普渡河-滇池断裂以西,岩浆活动强烈导致该区地壳结构复杂,具有"多层结构"的特点。据统计,赋存在昆阳群中的铅锌矿床(点)有近20处,其赋矿地层主要为:大龙口组(Pt_2d)、黑山头组(Pt_2hst)、鹅头厂组(Pt_2e)。本文优选大笑、热水塘硫铅同位素进行系统分析对比,总结指示成矿流体与指示物质来源。研究结果显示:赋存在前震旦纪铅矿矿床~(34)S值变化范围在6.33‰~14.99‰,成矿流体的总硫同位素值(δ~(34)SΣS)12.17‰。由此可见,赋存在前震旦纪地层中铅锌矿床硫化物主要为混合硫来源,硫同位素的来源具有多源性的特点。东川大笑铅锌矿:~(206)Pb/~(204)Pb变化范围为18.282~18.391,~(207)Pb/~(204)Pb变化范围为15.491~15.515,208Pb/204Pb变化范围为38.287~38.326,主要分布于地幔、造山带演化线。热水塘铅锌矿:~(206)Pb/~(204)Pb变化范围17.702~18.512,~(207)Pb/~(204)Pb变化范围15.626~15.72,~(208)Pb/~(204)Pb变化范围37.504~38.528,主要分布在造山带演化线附近。μ、ω值的变化范围表明所分析样品铅同位素均属于异常铅,说明其成矿物质多来源。因此,铅同位素主要来自地幔、上地壳和造山带,暗示成矿物质来源具有多源型特点。
[Abstract]:The preSinian system in central Yunnan is mainly located in the southwestern margin of Yangtze block, east of Yuanmou-Luzhujiang fault and west of Puduhe-Dianchi fault. Magmatic activity strongly causes the crustal structure in this area to be complicated and has the characteristics of "multi-layer structure". According to statistics, there are nearly 20 Pb-Zn deposits (points) in Kunyang Group. The main ore-bearing strata are: Datong formation (2d), Keshantou formation (PtStup 2hst), Yetouchang formation (Pt2e). In this paper, the sulfur and lead isotopes in hot water pond were systematically analyzed and compared, and the sources of indicating ore-forming fluids and indicating substances were summarized. The results show that the variation range of ~ (34) S value is 6.33 鈥，

本文编号：2112474