吉林延边五凤金矿地质特征及矿床成因

五凤金矿床是位于延边地区的浅成低温热液金矿床。矿脉的产出受不同方向断裂构造控制,主要分布于碱长花岗岩、角闪安山岩等侵入体及地层之中。研究表明,热液金矿化可分为石英--冰长石--方解石阶段,石英--方解石1阶段,石英--方解石2阶段及方解石阶段4个阶段。流体包裹体研究表明,研究区主成矿阶段石英中主要发育气液两相流体包裹体;其均一温度范围为129.8℃~236.5℃,峰值区间为190℃~220℃,盐度w(NaCl)为0.83%~1.98%。成矿流体为低温、低盐度的NaCl--H2O体系热液。氢氧同位素研究结果表明,五凤金矿床成矿流体为岩浆热液与大气降水的混合流体,矿床属浅成低温热液成因类型。

Geological characteristics of Wufeng gold deposit in Yanbian of Jilin and its genesis

Wufeng gold deposit is an important epithermal gold deposit in Yanbian area． The gold-bearing quartz veins are controlled by faults with different directions，which occur mainly in intrusive bodies such as alkali- feldspar granite and hornblende- andesite． The present study shows that the mineralization can be divided into four metallogenic stages: quartz- adularia-calcite phase，quartz-calcite phases ① and ②，and calcite phase． The study of fluid inclusions indicates there developed gas-liquid two-phase fluid inclusions from quartz in the main mineralization in studied area，of which the homogenization temperature ranges from129. 8℃ to 236. 5℃，while the peak value between 190℃ to 220℃，the salinity w (NaCl) varies from 0. 83% to 1. 98%． The ore-forming fluid is a kind of NaCl- H2O solution at low- temperature and low- salinity． The results of hydrogen and oxygen isotopes reveal that the ore- forming fluid is a kind of mixed fluid consisting of atmospheric precipitation and magmatic hydrother- mal． The Wufeng gold deposit is epithermal in origin．