青海德尔尼铜(钴)矿床矿石矿物特征及其地质意义  

Characteristics of Ore Minerals of De′erni Cu(Co)Deposit in Qinghai and Their Geological Significance

作　　者：段俊[1] 钱壮志[1,2] 黄喜峰[1] 董富权[3] 赵晓健[4] 鲁浩[1] 

机构地区：[1]长安大学地球科学与资源学院,陕西西安710054 [2]长安大学西部矿产资源与地质工程教育部重点实验室,陕西西安710054 [3]中国人民武警黄金第十一支队,湖南宁乡410600 [4]西安地质矿产研究所,陕西西安710054

出　　处：《地球科学与环境学报》2014年第1期201-209,共9页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(41072058;41372101);中国地质调查局地质大调查项目(1212011120354)

摘　　要：青海德尔尼铜（钴）矿床赋存于东昆仑阿尼玛卿蛇绿岩套中部，岩石类型主要有蛇纹石化的方辉橄榄岩、纯橄榄岩和二辉橄榄岩，矿石类型主要为块状、条带状含铜黄铁矿矿石，矿床成因存在多种认识。通过野外详细观察、室内显微镜下矿石矿物特征鉴定以及电子探针分析，确定德尔尼铜（钴）矿床的矿石矿物主要为黄铁矿，其次为磁铁矿、磁黄铁矿、黄铜矿、闪锌矿和方铅矿等，矿石结构以半自形粒状结构为主；钴元素在早期黄铁矿中比较富集，晚期黄铁矿中较贫，w（Co）/w（Ni）值指示黄铁矿与巴西 Sossego铁氧化物铜金矿一致；早期黄铁矿、黄铜矿、闪锌矿的微量元素质量比值指示矿床成矿温度为200℃～300℃，属于中温环境，进一步证明了该矿床不是岩浆型矿床，属于海底喷流沉积成因。矿床成矿过程可划分为4个阶段：海底喷流沉积阶段、构造变形阶段、热液阶段和表生氧化阶段，其中前两个阶段为铜、钴、锌的主要成矿期。De＆#39;erni Cu （Co）deposit in Qinghai is hosted in the middle of A＆#39;nyemaqen ophiolite suite,East Kunlun.The types of rocks are dominantly serpentinized harzburgite,dunite and lherzolite,the types of ores are mainly massive and banded copper-bearing pyrite,and there are different cognitions on the genesis of deposit.According to the detailed field observations, identifications under microscope for ore minerals and electron microprobe analysis,the main ore minerals in De＇erni Cu （Co）deposit are pyrite,the second ones are magnetite,chalcopyrite, sphalerite and galena, etc., and the structures of ores are mainly hypidiomorphic granual texture.Co is rich in the early period forming pyrite,and is poor in the late period forming pyrite;the values of w（Co）/w（Ni）indicate that pyrites are similar to Sossego iron oxide-copper-gold deposit in Brazil.The quality ratios of trace element in the early period forming pyrite,chalcopyrite,sphalerite indicate that the ore-forming temperatures are 200 ℃-300 ℃,and belong to the middle temperature environment,so that it is further proved that the genesis of deposit is independent from magmatism,but similar to the submarine exhalation-sedimentation.The ore-forming processes include four stages：submarine exhalation-sedimentation,tectonic deformation, hydrothermal and supergene oxidized stages, and the former two stages are the dominate mineralization period of Cu,Co and Zn.

关 键 词：铜(钴)矿床 矿床成因 电子探针分析 蛇绿岩 中温热液环境 成矿阶段 海底喷流 沉积 青海 

分 类 号：P618.41[天文地球—矿床学] P618.62[天文地球—地质学]