河南省老湾金矿床地球化学特征及矿床成因  

Geochemical Characteristics and Genesis of the Laowan Gold Deposit in Henan Province

作　　者：陈良[1] 戴立军[2] 王铁军[2] 罗平[1] 夏国体 

机构地区：[1]中国地质大学地球科学与资源学院,北京100083 [2]中钢集团天津地质研究院,天津300061 [3]中国冶金地质总局昆明地质勘查院,云南昆明650203

出　　处：《现代地质》2009年第2期277-284,共8页Geoscience

基　　金：国家自然科学基金重点项目(40434011)

摘　　要：在详细分析河南省老湾金矿床成矿地质背景、矿床地质特征的基础上,研究该矿床流体包裹体和氢、氧、硫、铅同位素,结果表明该金矿床的成矿流体为中低温、低盐度的富CO2的K+-Na+-C l--SO42-体系。氧、氢同位素分析显示,成矿流体1δ8O值变化于-5.25‰^+5.37‰,δD变化于-67‰^-76‰,表明成矿流体主要来源于岩浆水和大气降水;硫化物的3δ4S值变化于-0.1‰^+5.3‰,平均值为+3.98‰,显示深源硫的特征;Pb同位素组成显示铅主要来源于地幔,有少量地壳铅的加入。综合研究表明,老湾金矿床为受韧性剪切带控制的中—低温热液构造蚀变岩型金矿床。On the basis of detailed investigation of geological setting and ore deposit geologic features,this study analyses quartz-hosted fluid inclusions and oxygen and hydrogen isotope composition of quartz,as well as sulfur and lead isotope composition of sulfides from the Laowan gold deposit in Henan Province.The ore-forming fluid of the Laowan gold deposit is of the CO2-rich K＋-Na＋-Cl——SO2-4 system with middle-low temperature and low salinity.Oxygen and hydrogen isotope analyses show that δ18O and δD values range from-5.25‰ to ＋5.37‰ and-67‰ to-76‰,respectively,which indicates that the ore-forming fluid of the Laowan gold deposit is derived from magmatic and meteoric water.The δ34S values of sulfides associated with gold mineralization range from-0.1‰ to＋5.3‰ with a mean of ＋3.98‰,indicating typical signature of deep source sulfur.The characteristics of lead isotope indicate that it was mainly derived from the mantle,partly from the crust.Comprehensive research shows that Laowan gold deposit is a mesothermal-epithermal tectonic altered type gold deposit controlled by ductile shear zone.

关 键 词：地球化学 流体包裹体 成矿流体 矿床成因 老湾金矿 河南 

分 类 号：P618.51[天文地球—矿床学]