摘要
利用扫描电镜结合能谱分析技术以及电子探针分析技术,针对四川甘孜江浪矿田里伍铜矿床和黑牛洞铜矿床中伴生金元素的赋存状态进行分析。结果表明:金分布在两个矿床的致密块状矿石、角砾状矿石、条带状-网脉状矿石及黑色电气石黄铜矿矿石中,围岩中不含Au。且Au在矿石中质量分数变化大,其范围为0.1×10^(-6)~5.5×10^(-6)。Au以独立矿物银金矿和金银矿的形式赋存。银金矿颗粒较大,仅在里伍铜矿床的尾矿中发现,约90μm,银金矿中金含量为68.12%~70.79%。金银矿的粒径变化范围大,为:0.01μm^25μm,金银矿中金的含量范围大,为:5.14%~40.81%。金银矿在矿石中的赋存状态主要为以下3种:(1)与铋矿物(自然铋和铋银矿)共生;(2)包裹在金属硫化物中或嵌布在金属硫化物的粒间;(3)沿金属硫化物粒间充填。第一种金银矿的形成主要经历了温度高于400℃的体系,成矿流体中的Au,Bi均以氯络合物的形式运移,在温度降低的过程中,Au和Bi同时沉淀,从而形成金银矿与铋矿物的共生结构;第二种金银矿为温度降低过程中,随着硫化物的沉淀,Au-S络合物分解,使得Au沉淀;第三种金银矿应为主成矿期后的含Au,Ag的热液充填裂隙沉淀成矿的产物。
Scanning electronic microscope and electronic probe microscope were used to study the occurrence state of associated gold in Liwu and Heiniudong copper deposit in Sichuan. It was showed that Au was not distributed in country rocks, but in the compacted massive rock, berccia, stripped ~. stockwork rock and black tourmaline. The content of Au in these ore ranged form 0.1× 10^-6 to 5.5 × 10^-6 and Au occurred as electrum and kustelite. Electrum only appeared in tailings with a grain size of about 90μm, with gold content of 68.12%～70.79%. The grain size and con- tent of kustelite varied from 0.01 μm to 25 μm and 5.14% to 40.81%,respectively. There were three occurrence states for kustelite in the ore： （1） symbiosis with bismuth mineral （native bismuth and tapalpite）; （2） wrapped or inlayed in sulfide; （3） distributed between sulphide grain. The first occurrence of was resulted from recipitation of Au and Bi simultaneously. These two elements experienced high temperature above 400 ℃ in the from of Cl complex. The second occurrence resulted form the decomposition of Au-S complex when the temperature came down. The third occurrence formed from the precipitation of thermal fluid （with Au and Ag） after the main deposition of copper.
出处
《矿物岩石》
CAS
CSCD
北大核心
2017年第1期40-48,共9页
Mineralogy and Petrology
基金
中国地质调查局地质调查项目(1212011120267)
中国地质调查局地质矿产调查评价专项科技项目(1212011221073)
成都地质矿产研究所青年基金项目(2010-01)
