胶东金矿床中关键金属超常富集特征与机理初探  

A preliminary study of extreme enrichment of critical elements in the Jiaodong gold deposits,China

作　　者：杨立强[1] 李瑞红[1,2] 高雪 邱昆峰[1] 张良[1] YANG LiQiang;LI RuiHong;GAO Xue;QIU KunFeng;ZHANG Liang(Slute Key laboralory of Gelogical Processes and Mineral Resources,China Unirersily of Geosciences,Bejing 100083,China;Key Laburalary of Gechemicul Explorstion,Minisry of Naturul Resources,Insitute of Geophysical and Geochemical Explorution,Chinese Academy of Geolagicul Scienes,langfang 065000.China)

机构地区：[1]中国地质大学地质过程与矿产资源国家重点实验室,北京100083 [2]自然资源部地球化学探测重点实验室,中国地质科学院地球物理地球化学勘查研究所,廊坊065000

出　　处：《岩石学报》2020年第5期1285-1314,共30页Acta Petrologica Sinica

基　　金：国家重点研发计划(2019YFA0708603、2016YFC0600107-4);国家自然科学基金项目(41230311、41572069);高等学校学科创新引智计划(BP0719021);中国地质大学地质过程与矿产资源国家重点实验室专项基金(MSFGPMR201804)联合资助.

摘　　要：胶东是全球唯一已知发育于前寒武纪变质地体内的晚中生代巨型金矿省,也是当今世界仅有的探明金资源储量超过5000吨的三个金矿省之一,被视为检验巨型金矿床成矿新理论和新模型的关键地区。胶东金矿床长期的开发和研究主要聚焦于金,对其共/伴生关键金属尚缺乏关注;但广泛发育含关键元素Te、Re、W、Zr、Cr、La、Ce、Sb、Bi和As的独立矿物。通过对胶东典型金矿床内关键元素赋存状态的分析,发现它们主要以微米矿物集合体、纳米颗粒或类质同象固溶体的形式出现,且空间分布极不均匀。通过对12个典型金矿床内关键元素的含量分布和富集特征的初步研究表明,相对于华北克拉通的地壳元素丰度,本次分析的Cr、Co、Cd、Rb、Nb、Ta、Hf、W、Sn、Sb、Bi、As和除Ho之外的其它15种REE均发生了不同程度富集。其中,Sb超常富集与Au共生形成浅成造山型金锑矿床,暗示该区可能成为重要锑资源接替区;Cd、Co、Nb、Rb、As和Bi超常富集达到伴生组分综合评价品位,显示出良好的资源潜力,尤其是Cd已具备综合利用的资源条件;Cr、Se、Te、Re、W和LREE超常富集接近伴生组分综合评价品位或已发现超常富集的载体矿物,可作为未来潜在的接替资源;而Ta、Hf、Sn和HREE远低于伴生组分综合评价品位,且载体矿物过于稀少和细小或尚未被发现,发生超常富集的可能性相对较低。虽然目前对胶东金矿床中关键元素赋存状态和分布规律的研究极其薄弱,对其超常富集机理的研究尚属空白;但胶东金成矿系统的勘查和研究积累厚实、资料丰富,且其内蕴藏的矿石量巨大、已有矿业基础设施和选矿设备完善、选矿工艺先进。深入研究胶东金矿床中关键元素源-运-聚超常富集机理,可为丰富"非常规类型关键元素成矿系统"理论体系和胶东及类似金矿床中关键元素的综合利用提供理论基础。Jiaodong is a unique world-known Late Mesozoic giant gold province hosted in the Precambrian metamorphic terrane. It contains proven gold reserves of more than 5,000 tons,being the top three gold provinces in the world,and is regarded as a representative area to test the new metallogenic theory and genetic model of giant gold deposits. Although the long-term utilization and research in Jiaodong almost exclusively focused on gold and ignored its coexisted critical elements, several new findings of tellurosulphides and a series of independent minerals containing the critical elements Te,Re,W,Zr,Cr,La,Ce,Sb,Bi,and As were identified. Our studies on the occurrence of critical elements within several typical gold deposits in Jiaodong reveal that the critical elements tend to be fined minerals coexisted with other minerals to form complex mineral assemblages. The critical elements nanoparticles are also hosted on the crystalline surface of other minerals,in the micro-cracks,and as solid solution in the crystal structures. In this contribution,the distribution and enrichment of critical elements in 12 gold deposits in Sanshandao,Jiaojia,and Zhaoping gold belts were preliminarily studied. Compared with the average crustal abundances in North China Craton,critical elements Cr,Co,Cd,Rb,Nb,Ta,Hf,W,Sn,REEs( except Ho),Sb,Bi,and As have different degrees of enrichment. The enrichment of Sb and Au formed the epizonal medium-temperature vein-type gold-antimony deposit,suggesting that it has substantial antimony resources to be substituted. The Cd,Co,Nb,Rb,As,and Bi are enriched to be utilized in a comprehensive way,showing high resource potentials,especially that Cd is enriched to economic grade. The Cr,Se,Te,Re,W,and LREE were found to be extremely enriched in hosted minerals and may be comprehensively utilized. Ta,Hf,Sn,and HREE have lower degree of enrichment and are far lower than the comprehensive evaluation level. Their host minerals are too fined or have not yet been discovered. The occurrence and distribution as well as

关 键 词：关键金属 元素组合 超常富集机理 非常规类型关键元素成矿系统 胶东金矿床 

分 类 号：P618.6[天文地球—矿床学] P618.7[天文地球—地质学]