现代地质
現代地質
현대지질
GEOSCIENCE-JOURNAL OF GRADUATE SCHOOL CHINA UNIVERSITY OF GEOSCIENCES
2010年
1期
18-25
,共8页
金洞沟金矿床%低温热液型金矿床%矿床地球化学%矿床成因%四川平武县
金洞溝金礦床%低溫熱液型金礦床%礦床地毬化學%礦床成因%四川平武縣
금동구금광상%저온열액형금광상%광상지구화학%광상성인%사천평무현
Jindonggou gold deposit%epithermal deposit%geochemistry of mineral deposit%genesis of the deposit%Pingwu County%Sichuan Province
金洞沟金矿床是位于四川省北部平武县境内的小型岩金矿床.在详细研究矿床地质特征的基础上,测试了石英包裹体均一温度、盐度、化学成分及H、O同位素组成,分析了金属硫化物(黄铁矿、方铅矿、闪锌矿)的S同位素组成,对金的成矿作用进行了深入探讨.研究结果表明:金洞沟金矿床为低温热液型金矿床,其成矿物源主要是志留系茂县群浅变质碎屑岩系,矿石中硫化物以黄铁矿为主,硫化物含量约1%,为少硫化物型矿石.流体包裹体及S、H、O同位素研究显示成矿流体是主要由大气降水组成的热液,成矿温度为125~185 ℃,平均温度为148.7 ℃,属低温热液型金矿床.在此基础上,提出金洞沟金矿床的成矿作用经历了原始含矿岩系(矿源层)的形成、区域变质作用衍生矿源层的形成、热液成矿作用及表生氧化富集等4个阶段,韧性剪切构造活动是引起金活化、迁移和富集的主要因素.该成果为该矿床成因的认识和找矿工作提供了参考.
金洞溝金礦床是位于四川省北部平武縣境內的小型巖金礦床.在詳細研究礦床地質特徵的基礎上,測試瞭石英包裹體均一溫度、鹽度、化學成分及H、O同位素組成,分析瞭金屬硫化物(黃鐵礦、方鉛礦、閃鋅礦)的S同位素組成,對金的成礦作用進行瞭深入探討.研究結果錶明:金洞溝金礦床為低溫熱液型金礦床,其成礦物源主要是誌留繫茂縣群淺變質碎屑巖繫,礦石中硫化物以黃鐵礦為主,硫化物含量約1%,為少硫化物型礦石.流體包裹體及S、H、O同位素研究顯示成礦流體是主要由大氣降水組成的熱液,成礦溫度為125~185 ℃,平均溫度為148.7 ℃,屬低溫熱液型金礦床.在此基礎上,提齣金洞溝金礦床的成礦作用經歷瞭原始含礦巖繫(礦源層)的形成、區域變質作用衍生礦源層的形成、熱液成礦作用及錶生氧化富集等4箇階段,韌性剪切構造活動是引起金活化、遷移和富集的主要因素.該成果為該礦床成因的認識和找礦工作提供瞭參攷.
금동구금광상시위우사천성북부평무현경내적소형암금광상.재상세연구광상지질특정적기출상,측시료석영포과체균일온도、염도、화학성분급H、O동위소조성,분석료금속류화물(황철광、방연광、섬자광)적S동위소조성,대금적성광작용진행료심입탐토.연구결과표명:금동구금광상위저온열액형금광상,기성광물원주요시지류계무현군천변질쇄설암계,광석중류화물이황철광위주,류화물함량약1%,위소류화물형광석.류체포과체급S、H、O동위소연구현시성광류체시주요유대기강수조성적열액,성광온도위125~185 ℃,평균온도위148.7 ℃,속저온열액형금광상.재차기출상,제출금동구금광상적성광작용경력료원시함광암계(광원층)적형성、구역변질작용연생광원층적형성、열액성광작용급표생양화부집등4개계단,인성전절구조활동시인기금활화、천이화부집적주요인소.해성과위해광상성인적인식화조광공작제공료삼고.
Jindonggou gold deposit is a small gold deposit located in Pingwu County,north of Sichuan Province. Based on a studied geological characteristics of the Jindonggou gold deposit,the authors measured the homogenization temperature,salinity,chemical composition,as well as H and O isotopic compositions of the fluid inclusions of the quartz, measured S isotopic composition of the metal sulfide(pyrite,galena and sphalerite),and systematically discussed the metallogenesis of the gold deposit. The results show that the deposit belongs to epithermal gold deposit type. The ore-forming source comes from the epimetamorphic clastic rocks of Smx(Silurian System). This gold deposit is characterized by a poor content of sulfide minerals (below 1%). Metallogenic fluid is composed of atmospheric precipitation. The homogenization temperature of fluid inclusions ranges from 125 ℃ to 185 ℃,belonging to epithermal gold deposit type. The metallogenesis of the Jindonggou gold deposit is divided in to four stages,i.e.the formation of gold source bed in the sedimentation,the formation of derivative gold source bed in the regional metamorphism, the formation of the gold deposit in the hydrothermalism and hypergenesis. The regional shear zone movement is likely the major factor leading to activation,migration and concentration of Au. The conclusions are significant for realization of the deposit genesis and mineral exploration.