四川天宝山铅锌矿床成因研究及区域成矿动力学背景探讨

发布时间：2018-06-10 08:15

  本文选题：天宝山铅锌矿床 + 成矿阶段　； 参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：天宝山铅锌矿床位于扬子板块西南缘,是川滇黔铅锌矿集区的重要组成部分之一。本文通过野外观察、室内鉴定、地球化学等方法,系统研究天宝山铅锌矿床的成因,并对区域铅锌成矿动力学背景进行初步的探讨。天宝山铅锌矿床产在震旦系灯影组白云岩地层中,具有后生成矿特征,矿体受构造断裂控制明显,矿区内岩浆岩不发育,未见中酸性侵入岩,仅发育辉绿岩脉。根据矿石、矿物组合特征及其组构和穿插关系,将成矿期次划分为黄铜矿-闪锌矿-黝铜矿-毒砂阶段和闪锌矿-方铅矿-黄铁矿-方解石阶段,其中黄铜矿-闪锌矿-黝铜矿-毒砂阶段的成矿温度为300~370℃,为中-高温热液成矿,闪锌矿-方铅矿-黄铁矿-方解石阶段成矿温度为150~250℃,为中-低温热液成矿。硫化物δ34S值指示成矿流体中的硫来源于岩浆热液,成矿晚期脉石方解石的C-O同位素指示该阶段成矿热液中的碳和氧来源于溶解了海相碳酸盐岩的沉积建造水和岩浆热液混合。不同成矿阶段的闪锌矿微量元素特征指示黄铜矿-闪锌矿-黝铜矿-毒砂阶段具有岩浆热液成矿特征,闪锌矿-方铅矿-黄铁矿-方解石阶段具有低温热液成矿特征。因此认为,天宝山铅锌矿床属于中温热液脉型铅锌矿床,前期主要是岩浆热液参与成矿,后期有地层建造水和大气降水加入。前人研究川滇黔矿集区铅锌矿床的成矿年龄在190~230Ma之间,本文对区域上三叠系碎屑岩进行综合研究,厘定了区域铅锌成矿的动力学背景。研究结果显示,川滇黔矿集区三叠系盆地沉积环境与铅锌成矿构造动力学背景相一致,形成于印支期造山运动背景下。印支造山运动引起板块碰撞拼合,产生强烈挤压作用,导致越北古陆和江南古陆抬升被剥蚀,碎屑物源向内陆搬运并沉积成岩,同时盆地流体向内陆运移,深部流体沿构造断裂上升,在川滇黔接壤区沉淀成矿。
[Abstract]:Tianbaoshan lead-zinc deposit is located in the southwest margin of Yangtze plate and is one of the important components of Sichuan Yunnan Guizhou lead-zinc deposit concentration area. By means of field observation, laboratory identification and geochemistry, this paper systematically studies the genesis of Tianbaoshan lead-zinc deposit, and preliminarily discusses the dynamic background of regional lead-zinc mineralization. The Tianbaoshan lead-zinc deposit occurs in dolomite strata of Dengying formation of Sinian system and has the characteristics of post-forming ore deposits. The orebody is obviously controlled by structural faults, magmatic rocks are not developed in the mining area, no intermediate-acid intrusive rocks are found, but only diabase veins are developed. According to the characteristics of ore and mineral assemblages and their fabric and intercalation relationships, the metallogenic stages are divided into chalcopyrite, sphalerite, tetrahedrite and arsenopyrite, and sphalerite galena, pyrite and calcite. The metallogenic temperature of chalcopyrite-sphalerite-pyrite-arsenopyrite stage is 300 ~ 370 鈩，

本文编号：2002555