热化学硫酸盐还原作用(TSR)与贵州汞(金锑)矿床成因机制再探讨——从黔东锰矿古天然气渗漏沉积成矿理论得到的启示  

Sulfate thermochemical reduction (TSR) and rediscussion on the formation mechanism of mercury (gold /antimony) deposits in Guizhou——Inspiration from the theory of paleo-gas seepage-sedimentary mineralization of manganese deposits in eastern Guizhou

作　　者：陈履安 周琦[1,3] CHEN Lvan;ZHOU Qi(Geological Society of Guizhou Province,Guiyang, 550004;Guizhou Bureau of Geological and Mineral Exploration and Development, Guiyang, 550004;The Laboratory of Geological and Mineral Resource Center of Guizhou Province, Guiyang, 550018)

机构地区：[1]贵州省地质学会,贵阳550004 [2]贵州省地质矿产中心实验室,贵阳550018 [3]贵州省地质矿产勘查开发局,贵阳550004

出　　处：《地质论评》2019年第2期431-437,共7页Geological Review

基　　金：中国地质调查局"贵州省矿产资源调查成果综合集成与服务产品开发"(编号:DD20160346-28);"贵州锰矿成因与成矿规律"(编号:DD20160346-54);贵州省锰矿资源预测评价科技创新人才团队(编号:黔科合平台人才[2018]5618)项目的成果~~

摘　　要：受黔东地区南华纪锰矿的古天然气渗漏成矿理论启示,在研究贵州典型汞矿成矿作用的地球化学机理的基础上,本文将热化学硫酸盐还原反应(TSR)引入成矿过程。提出富含汞(包括气态汞)、还原硫、Cl^-的含矿—运矿流体与含汞围岩相互作用,进一步论证推断深部油气藏的圈闭体系和围岩都可能是汞的重要来源。在较高温度条件下,有油气(烃类)参与的硫酸盐热化学还原作用是还原硫(H_2S、HS^-、S^(2-))的主要来源,而油气(烃类)在成矿作用中发挥了还原剂的重要作用。含矿的热流体(藏)渗漏或者喷溢,同时又溶解流经围岩中以辰砂、单质汞等形式存在的汞,转变为可溶解的汞—硫配合物而运移,在系统从封闭转为开放的构造作用下,气体组分逸失,在还原硫浓度m(S^(2-))降低、Eh升高、pH降低、压力和温度降低以及盐度降低等物理化学条件下成矿。类比研究显示,贵州一些金、锑等金属矿床具有与此类汞矿床类似的成矿机理。故20世纪80年代以来的这类(汞、金、锑)金属矿床的沉积—改造成因及作者提出的相关地球化学机理应当加以适当修正。The study of sulfate thermochemical reduction reaction(TSR) was introduced into the mineralization process, inspired by the theory of paleo-gas percolation and sedimentary mineralization of the manganese ore in eastern Guizhou, based on the study of the geochemical mechanism of the mineralization of mercury depsides in Guizhou. It is further demonstrated that the source of mercury can be either the trap system of deep reservoirs or the surrounding rocks(such as Qingxudong Formation, which varies with specific deposits). The ore-forming fluid is transported by the ore-transporting fluid which is riched in mercury(including gaseous mercury), sulfur reduction and Cl-, and also interacts with mercury in the surrounding rocks as the form of cinnabar and elemental mercury. The thermal chemical reduction of oil and gas(hydrocarbons) and sulfate at higher temperatures is the source of reducing sulfur(H2S, HS-, S2-). Oil and gas(hydrocarbons) play an important role as reducing agent in mineralization. Due to leakage or spillage of the mineral bearing hot fluid(reservoir), the fluid also dissolves the mercury in the form of cinnabar and elemental mercury at flow through the surrounding rocks, by migration of mercury into soluble mercury-sulfur complexes. Mineralization occurred at geological conditions in the system from closed to open(structure), and gas composition nonvolatile, in m(S2-) reduce elevated, Eh, pH, lower, lower pressure and temperature and salinity decrease such as physical and chemical conditions. The results show that the metallogenic mechanism of gold, antimony and other metal deposits in Guizhou is similar to that of mercury deposit. Therefore, the sedimentation-alteration origin of this kind of(mercury, gold and antimony) metal deposits since 1980 s, especially the geochemical mechanism proposed by the author should be improved.

关 键 词：热化学硫酸盐还原反应(TSR) 古天然气渗漏沉积作用 汞矿床 金矿床 锑矿床 油气 成矿作用 地球化学机理 贵州 

分 类 号：P611[天文地球—矿床学]