吉林海沟金矿床成因及找矿勘查模式:黄铁矿LA-ICP-MS微量元素及硫同位素证据  

Genesis and ore prospecting model of Haigou gold deposit in Jilin Province:evidence from LA-ICP-MS trace element and sulfur isotopic analysis of pyrite

作　　者：陈原林 李欢[1,2] 郑朝阳[3] 努尔喀纳提·马达依普[1,2] KHAN Rehan CHEN Yuanlin;LI Huan;ZHENG Chaoyang;MAOAYIPU Nuerkanati;KHAN Rehan(School of Geosciences and Info-Physics,Central South University,Changsha 410083,China;Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,Central South University,Changsha 410083,China;College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China)

机构地区：[1]中南大学地球科学与信息物理学院,湖南长沙410083 [2]中南大学有色金属成矿预测与地质环境监测教育部重点实验室,湖南长沙410083 [3]贵州大学资源与环境工程学院,贵州贵阳550025

出　　处：《中南大学学报（自然科学版）》2021年第9期2990-3002,共13页Journal of Central South University:Science and Technology

基　　金：国家重点研发计划项目(2016YFC0600104)。

摘　　要：吉林海沟金矿床大地构造上位于华北克拉通与兴蒙造山带交汇部位,处于中生代NE向断裂(太平洋构造域)与EW向断裂构造(古亚洲洋构造域)的交汇部位,是中国东北地区最大的金矿床之一。自20世纪60年代被发现以来,前人对其成因提出了多种不同的认识,严重制约了深部及外围地质找矿工作。本文以海沟金矿床成矿期黄铁矿为研究对象,在野外地质调查的基础上,通过显微观测、激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)原位微量元素点测试、元素扫面分析和硫同位素实验,揭示黄铁矿中不同微量元素的赋存状态,为矿床成因提供新的约束。根据研究区侵入体产状、矿体分布、构造展布特征以及流体演化规律,建立海沟金矿床的矿床成因及找矿勘查模式,为深部地质找矿提供科学证据。研究结果表明:海沟金矿床多金属硫化物石英脉中的金主要以自然金的形式存在;黄铁矿中的Au与Ag,Te,Bi和Pb相关性较好,指示这些元素主要是以类质同象的方式赋存于黄铁矿晶格中;海沟金矿床硫源至少有2种,一种是总硫δw(34S)接近于0的幔源或深部地壳源,另一种是总硫δw(34S)介于−12‰~−6‰之间的中上地壳源,海沟较负的硫同位素值与海沟矿区出现的大量脉岩和围岩(主要为色洛河群地层)直接相关;海沟金矿床是一种与岩浆热液、变质热液有关的石英脉型金矿床。Haigou gold deposit is located in Jilin Province,which is one of the largest gold deposits in the Northeast China.Tectonically,this deposit locates at the junction of North China Craton and Xingmeng Orogenic Belt,and Mesozoic NE-trending fault(Pacific tectonic domain)and EW-trending fault structure(Palaeo-Asian ocean tectonic domain).After 1960s,a variety of different views about this deposit was put forward,which severely restricted the deep and peripheral ore prospecting.In this study,pyrite of Haigou gold deposit was taken as the main research object,and the geological field survey,microscopic observation,LA-ICP-MS in-situ trace element and sulfur isotopic analysis revealed the occurrence of different trace elements in pyrite and provided new constraints for the genesis of gold deposit.According to the occurrence of intrusions,the distribution of ore bodies,characteristics of structural distribution and the regular patter of fluid evolution in the study area,the genesis and ore exploration model of Haigou gold deposit was established,which provided scientific evidence for further deep geological prospecting of the deposit.The results show that the gold in polymetallic quartz-sulfide veins of the Haigou gold deposit mainly exists in the form of natural gold.The positive correlation of Au in pyrite with Ag,Te,Bi and Pb indicates that these elements mainly occur in pyrite lattice in the form of isomorphism.There are at least two sulfur sources in Haigou gold deposit,one is mantle or deep crust source with total sulfurδw(34S)close to zero,and the other is the middle and upper crust source with total sulfurδw(34S)between−12‰and−6‰.The large negative value ofδ34S may be due to a large number of dykes and country rocks(mainly the Seluohe Group)in Haigou area.Haigou gold deposit is a quartz-vein type gold deposit associated with magmatic and metamorphic hydrothermal fluids.

关 键 词：微量元素 元素Mapping面扫描分析 激光剥蚀电感耦合等离子体质谱(LA-ICP-MS) 矿床成因 找矿勘查模式 金矿床 

分 类 号：P578.292[天文地球—矿物学] P618.51[天文地球—地质学]