摘要
黄铁矿是热液金矿主要的载金矿物。单个金矿中黄铁矿的载金已有不少研究,并积累了相关经验,但综合研究和相对定量的分析鲜见,对热液金矿中黄铁矿含金性的普遍认识非常重要。以我国数十个重要的卡林/类卡林型、造山型、岩浆热液型以及浅成低温热液型金矿中载金黄铁矿的矿物学及元素组成为基础,相对全面和定量地开展了黄铁矿粒径、自形程度和As含量与其载金性之间相关性的研究。结果表明:黄铁矿的载金性与其粒径大小多呈负相关(相关系数为-0.049^-0.783),与其自形程度多呈负相关(相关系数为-0.049^-0.989),与其As含量多呈正相关(相关系数为0.189~0.998),即细晶、它形、高As黄铁矿载金性优于粗晶、自形、低As的黄铁矿。相较于粗晶自形的黄铁矿,中细晶它形黄铁矿晶体,由于非理想的生长条件,使其内部晶格缺陷常见,从而更易包裹自然金;As以类质同象的形式置换S进入黄铁矿,由于As与S的晶体化学性质差异,导致高As黄铁矿内部出现更多晶格缺陷而捕获金。这些可能都是导致细晶、它形、高As黄铁矿载金性优于粗粒、自形、低As黄铁矿的原因。热液金矿成矿早阶段形成黄铁矿中的不可见金,很可能在热液系统中通过溶解、迁移、再沉淀等过程,而转变为可见金。
Pyrite is the main auriferous mineral in hydrothermal gold deposits.The auriferous properties of pyrite have been researched in many single deposits and some related experiences were accumulated.But it's rare of the synthetic and quantitative studies and an universal understanding about properties of auriferous pyrite is paid much attention.In this paper,based on mineralogy and chemical compositions of pyrite in various types(including Carlin,orogenic,magmatic-hydrothermal and epithermal gold deposits)of hydrothermal gold deposits in China,the quantitative and comprehensive studies about auriferous properties of different grain sized,various crystalline form and varied As contents pyrite have been conducted.It\s suggested that the auriferous properties of pyrite are mostly negative correlated with its grain size(the correlation coefficients range from-0.049 to-0.783)and idiomorphic degree(correlation coefficients range from-0.049 to-0.989),positive correlated with its As contents(correlation coefficients range from 0.189 to 0.998).The auriferous properties of fine grain,allotriomorphic crystal form and high As contents pyrite are mainly better than that of coarse grain,idiomorphic crystal form and low As contents pyrite.Compared with the coarse and idiomorphic crystal form pyrite,the fine grain and allotriomorphic crystal form pyrite can easily wrap up gold in its lattice defects formed in non-ideal growth conditions.The high As contents pyrite mainly formed through As isomorphism substituting S in pyrite and can easily produce lattice defects,in which the gold hosted,because of the different chemical property of As and S.These may be some reasons for the auriferous properties of pyrite above.The invisible gold in the pyrite may convert into visible one by dissolving,migration and reprecipitation in hydrothermal systems.
作者
刘一浩
薛春纪
赵云
赵晓波
褚海霞
刘城先
余亮
王璐
吴得海
LIU Yihao;XUE Chunji;ZHAO Yun;ZHAO Xiaobo;CHU Haixia;LIU Chengxian;YU Liang;WANG Lu;WU Dehai(School of Earth Sciences and Resources,State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Beijing 100083,China;School of Prospecting and Surveying Engineering,Changchun Institute of Technology,Changchun,Jilin130021,China;No.1 Geological Team,Xinjiang Bureau of Geology and Mineral Resources,Changji,Xinjiang831100,China)
出处
《现代地质》
CAS
CSCD
北大核心
2020年第1期1-12,共12页
Geoscience
基金
国家重点研发计划项目(2017YFC0601202)
关键词
晶体特征
砷含量
载金黄铁矿
热液金矿
中国
crystal characteristics
As content
auriferous pyrite
hydrothermal gold deposit
China
