上黑龙江盆地虎拉林金矿床黄铁矿LA-ICP-MS原位测试及其对矿床成因的制约  

LA-ICP-MS Analysis of Pyrite from Hulalin Gold Deposit in the Upper Heilongjiang Basin and its Implication on Genesis of the Deposit

作　　者：巩鑫 魏小勇 赵元艺[2] 刘春花[2] 水新芳 杜蔺 宋小军 衮民汕 谭伟 GONG Xin;WEI Xiaoyong;ZHAO Yuanyi;LIU Chunhua;SHUI Xinfang;DU Lin;SONG Xiaojun;GUN Minshan;TAN Wei(Geological and Mineral Exploration Institute,Guizhou Bureau of Geological Exploration for Non-ferrous Metals and Nuclear Industry,Guiyang 550005,Guizhou,China;MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;Harbin Center for Integrated Natural Resources Survey of China Geological Survey,Harbin 150086,Heilongjiang,China)

机构地区：[1]贵州省有色金属和核工业地质勘查局地质矿产勘查院,贵州贵阳550005 [2]中国地质科学院矿产资源研究所,自然资源部成矿与资源评价重点实验室,北京100037 [3]中国地质调查局哈尔滨自然资源综合调查中心,黑龙江哈尔滨150086

出　　处：《大地构造与成矿学》2021年第4期745-760,共16页Geotectonica et Metallogenia

基　　金：国家重点研发计划“蒙古-鄂霍茨克洋构造体制成矿系统物质组成与过程”(2017YFC0601303)资助。

摘　　要：位于上黑龙江盆地内的虎拉林金矿床为区域重要的金矿床之一,关于该矿床的成因一直存在较大的争议。为厘清虎拉林金矿床成矿物质来源及赋存状态,确定矿床成因及形成机制,作者运用LA-ICP-MS原位测试技术,分析了矿床中不同期次黄铁矿的元素组成。结果表明,该矿床存在PyⅠ、PyⅡ和PyⅢ三期黄铁矿,不同期次黄铁矿的微量元素组成差异明显,PyⅡ为金主成矿期,其Cu、Pb、Zn、Ag、Au、Bi、As、Mo、V、Cr、Mn、Sb、Sn和Ga等微量元素含量较高。在PyⅠ、PyⅡ和PyⅢ三期黄铁矿中, Co、Ni、As、Se以类质同象形式赋存于黄铁矿中;而Cu、Pb、Zn、Bi及Te、Mo、V、Cr、Mn、Sb、Sn、Ga分别以金属矿物微粒及纳米微粒金属矿物包体存在于黄铁矿颗粒中或间隙;Au、Ag以银金矿微粒形式存在于黄铁矿晶体及间隙中,且As在Au的迁移、富集和沉淀等过程中具有重要的作用。三个不同期次黄铁矿的Co/Ni值均小于10,且在Co-Ni成因判别图中PyⅠ主要分布于沉积区, PyⅡ与PyⅢ则主要分布于沉积改造区及岩浆区。结合研究区区域地质背景、矿床地质特征及黄铁矿微量元素特征,认为虎拉林金矿床首先经历了早期沉积作用,之后受到来自含Au、Ag、Cu、Pb、Zn、Bi等元素成矿流体的热液叠加改造,成矿物质源于早白垩世深部岩浆,且成矿过程中存在岩浆热液与早期沉积地层的混染作用,是典型的斑岩型金矿床。The Hulalin gold deposit in the Upper Heilongjiang Basin is one of the most important gold deposits in the region,and the origin of the gold deposit is controversial.In order to identify and clarify the source and occurrence of gold,also to determine the genesis and formation mechanism of the gold deposit,the elemental composition of pyrite in different stages were analyzed by using LA-ICP-MS in-situ measurement technique.The results indicate that there are three phases of pyrite in this gold deposit,i.e.,PyⅠ,PyⅡ and PyⅢ,and different phases of pyrite have obviously different trace element compositions.PyⅡ is the main metallogenic stage of the gold deposit.Pyrite of PyⅡ stage has Cu,Pb,Zn,Ag,Au,Bi,As,Mo,V,Cr,Mn,Sb,Sn,and Ga contents higher than those of PyⅠ and PyⅢ.Co,Ni,As and Se occur as isomorphism substitution in the overall pyrite.Cu,Pb,Zn,Bi and Te,Mo,V,Cr,Mn,Sb,Sn,Ga occur as fine to metallic mineral particles or metal mineral nanoparticle inclusions in pyrite particles respectively.Au and Ag occur as silver-gold ore particles in pyrite crystal lattice or fractures.As plays an important role in migration,enrichment and precipitation of Au during gold mineralization.Co/Ni ratios of pyrite in three different periods are less than 10,and PyⅠ is mainly distributed in the sedimentary area,while PyⅡ and PyⅢ are mainly distributed in the sedimentary modification area and magma area of Co versus Ni plot.Combining the regional geological background of the study area,the geological characteristics of the gold deposit and the trace element characteristics of pyrite,we suggest that the metallogenesis of the Hulalin gold deposit includes the early sedimentation,and subsequent hydrothermal superimposition of fluids bearing Au,Ag,Cu,Pb,Zn,and Bi.It is believed that the ore-forming materials in the Hulalin gold deposit originated from the deep intrusion of the Early Cretaceous.In the process of mineralization,there is a contaminant effect of magmatic hydrothermal fluid and early sedimentary strata.Henc

关 键 词：黄铁矿 微量元素 LA-ICP-MS原位分析 虎拉林金矿床 上黑龙江盆地 

分 类 号：P611[天文地球—矿床学]