摘要
延边五凤五星山金(银)矿床是一个大型的典型低硫化型浅成低温热液金矿床。矿床由石英-方解石脉、石英脉以及细脉浸染状硫化物角砾状蚀变岩等矿体所组成;矿化可分为含黄铁矿块状石英、玉髓状石英脉、方解石-石英脉、方解石-沸石4个阶段,其中玉髓状石英脉阶段和方解石-石英脉阶段为主要成矿阶段。矿物流体包裹体的研究表明:(1)以气液两相包裹体为主,由孤立的原生包裹体和沿裂隙成串分布的次生包裹体构成;(2)均一温度为180~280℃;(3)盐度(w(NaCl))和密度分别为4.8%~7.02%,0.75~0.92 g/cm3;(4)成矿深度为0.15~0.32 km;(5)激光拉曼光谱实验获得流体包裹体的气相主要成分为水。结合氢氧同位素地球化学特征(δD值为-66‰^-98‰,平均为-87‰;δ18O值为3.18‰^-7.2‰,平均为-5.1‰),确定成矿流体是以水为主的循环大气水,受深部热流作用形成含矿热液,在伸展环境下沿断裂上升,在浅部由充填作用形成五凤石英-方解石脉、石英脉,深部通过沸腾作用形成五星山浸染状硫化物以及角砾状蚀变岩矿体。这与前人认为两矿区仅是通过沸腾作用而造成成矿物质沉淀的成矿观点有所不同。
The Wufeng- Wuxingshan gold （silver） deposit in Yanbian area, Jilin Province is a large epithermal gold deposit of low-sulphidation type. The deposit is composed mainly of quartz-calcite veins, quartz veins and veinlet-dissemination sulfide breccias in altered rocks. The mineralization can be divided into four metallogenic stages： pyrite-bearing bulk quartz,chalcedony quartz vein, calcite-quartz vein and calcite-quartz, with the second and third stages being the main ones. The study of the fluid inclusions from the deposit reveals that： （1） most of them are two-phase isolated primary inclusions and chained secondary inclusions along fractures in minerals; （2） homogeneous temperature is mostly 180- 280 ℃ （3）the salinity is 4.8 to 7.02 NaCl% and the density is 0.75 -0.92 g/cm^3 ; （4）the depth of the mineralization is at 0. 15 -0.32 km; （5）Laser Raman Spectroscopy analysis of the fluid inclusions reveals their predominant H2O constitute. These features of the fluid inclusions, combined with hydrogen and oxygen isotope studies （δD is - 66‰-- 98‰ , averaged at --87‰;δ^18O is 3.18‰--7.2‰ and averaged at --5.1‰）, suggest that the ore-forming fluids of the deposit came from the circulating atmospheric waters heated by the deep thermal flow. Under tensile tectonic regime, these hydrothermal fluids migrated through fault zones. Quartz - calcite veins and quartz veins were formed at the upper portion of the Wufeng deposit by filling while the veinlet-dissemination sulfides and breccias were formed at the lower portion of the deposit by fluid boiling. This opinion is different from the previous one that suggested the deposit was formed solely by fluid boiling.
出处
《吉林大学学报（地球科学版）》
EI
CAS
CSCD
北大核心
2008年第4期566-575,共10页
Journal of Jilin University：Earth Science Edition
基金
国家自然科学基金项目(40472050
40772052)
南京大学内生金属矿床成矿机制研究国家重点实验室实验基金(20062008)
关键词
流体包裹体
五凤五星山金(银)矿床
延边
fluid inclusion
Wufeng - Wuxingshan gold （silver） deposit
Yanbian
