山西繁峙义兴寨金矿黄铁矿成因矿物学特征及稳定同位素研究  

PYRITE TYPOMORPHIC CHARACTERISTICS AND STABLE ISOTOPE STUDIES OF YIXINGZHAI GOLD DEPOSIT IN FANSHI COUNTY,SHANXI PROVINCE,CHINA

作　　者：李成禄 李胜荣[2] 曲晖 罗军燕[2] 张聚全[2] 宋继叶[2] 

机构地区：[1]黑龙江省地质调查研究总院,黑龙江哈尔滨150036 [2]地质过程与矿产资源国家重点实验室,中国地质大学,北京100083

出　　处：《矿物岩石》2013年第1期1-7,共7页Mineralogy and Petrology

基　　金：国家自然科学基金重大研究计划重点支持项目(90914002);全国危机矿山接替资源找矿项目(20089937)

摘　　要：黄铁矿是重要载金矿物,其标型特征能够指示诸多成矿信息。针对义兴寨金矿中黄铁矿的化学成分、爆裂温度及S,Pb同位素等特征进行详细的研究,试图提取该矿床的成因及找矿信息。研究表明,黄铁矿化学成分中S/Fe,Au/Ag,Co/Ni,Fe/(S+As),δFe-δS,Co-Ni-As等成因标型显示该矿床属于中偏浅成岩浆热液型矿床,且目前所开采的位置处于矿体中下部位置;爆裂温度显示为中低温型矿床。硫同位素值在-3.2‰～+3.5‰,数值集中,接近陨石硫特点,铅同位素206Pb/204Pb值为16.524～16.628,207Pb/204Pb值为15.284～15.321 2,208Pb/204Pb值为36.686～36.812,显示成矿物质来源于上地幔与下地壳。结合本区的成岩、成矿年龄,显示该金矿床的形成与华北地区燕山期大规模的岩浆活动有密切关系。Pyrites are common and important gold-bearing minerals widely existing in gold deposits. Detailed research is made on typomorphic characteristics of pyrite from Yixingzhai gold deposit in Shanxi,China,including its chemical composition, decrepitation temperature and stable isotope. Results shows that chemical composition, major and trace elements in pyrites and S/Fe, Au/Ag, Co/Ni, Fe/（S＋ As）, δFe-δS, Co-Ni-As diagrams, have their own typical composition typomorphic characteristics. In fact,chemical composition of pyrite is rich in iron and low in sulfur, content of Au in pyrite is high,and the content of Ag in pyrite is low, both of them show reverse relations. According to the characteristics of pyrite composition,the outcropping ore bodies are located on the mid-low parts of mineralization centre. Co and Ni are widespread in pyrite and showing large variation of Co/Ni ratio ranging from 3.75 to 40, with average value of 10, indicating that the Yixingzhai deposit belongs to magrnatic hydrothermal type gold deposit. Fe/S＋As show that the mineralization environment is medium-shallow in depth. Co-Ni-As show the genetic types is shallow epithermal and magmatic hydrothermal one. Decrepitation temperature curves gives a good display on the change of hydrothermal fluids in different metallogenic stages,and the results of decrepitation temperature ranging 146 ℃ to 372 ℃ ,indicating that the Yixingzhai deposit belong to medium-low temperature deposit. The variation of S isotope is small, ranging from -3.200 to ＋3.5%,mainly 2%- 3% , characteristic of magmatic sulfur. Pb isotopic composition of ore is stable. The ^206Pb/^204pb, ^207pb/^204pb, ^208pb/^204pb values of ores Varied in a range of 16. 524-16. 628,15. 284-15. 3212 and 36. 686-36. 812 respectively. These data are plotted near the lower crust and upper mantle setting, consistent with Pb isotopic composition of magmatic rocks in the deposit. The evidence from the diorite complex body and mineralization age indicates that the gold mineralization cl

关 键 词：义兴寨金矿 黄铁矿 化学成分 爆裂温度 同位素 成因 

分 类 号：P578.292[天文地球—矿物学]