金顶超大型铅锌矿床稀散金属Cd、Tl的矿化富集规律及地质意义  

Enrichment of dispersed elements of Cd and Tl in the giant Jinding Zn-Pb deposit in Lanping County,western Yunnan Province,SW China and its geological significance

作　　者：刘靖坤 薛传东[1,2] 王维 薛力鹏 李国 张佳慧 潘东 LIU JingKun;XUE ChuanDong;WANG Wei;XUE LiPeng;LI Guo;ZHANG JiaHui;PAN Dong(Department of Earth Sciences,Kunming University of Science and Technology,Kunming 650093,China;Observation and Research Station of Basinal Brine and Petroliferous Fluid Coupling and Metallogeny at the Jinding Zinc-Lead Deposit in Lanping,Yunnan,Lanping 671400,China)

机构地区：[1]昆明理工大学地球科学系,昆明650093 [2]兰坪金顶铅锌矿盆地-油气流体成矿云南省野外科学观测研究站,兰坪671400

出　　处：《岩石学报》2025年第2期642-656,共15页Acta Petrologica Sinica

基　　金：第二次青藏高原综合科学考察研究项目(2021QZKK0301);云南省新一轮找矿战略行动计划项目(Y202405)联合资助.

摘　　要：金顶超大型铅锌矿床共(伴)生丰富的稀散元素Cd和Tl,其资源量分别为176.2kt、8.2kt,占全国总量(Cd 351kt,Tl 11.8kt)的50.2%、69.5%,但其富集规律及与主成矿元素(Pb、Zn和Fe)的成因联系尚不清楚,制约了找矿勘查和资源评价进程。本文尝试运用三维地质建模和空间分析方法,构建Cd、Tl和主成矿元素的地球化学模型,揭示北厂和架崖山两个主矿段中Cd、Tl的空间分布特征和富集规律,并阐明其与主成矿元素的成因联系。研究结果表明:(1)Cd与Zn、Tl与Fe分别具有相似的空间分布特征。(2)砂岩型和灰岩型矿体均富集Cd、Tl,但后者(单位体积金属量均值Cd 0.341t,Tl 0.022t)富集强度高于前者(Cd 0.141t,Tl 0.002t),且均集中分布于逆断层上盘围岩的张性空间中,并表现出多个富集中心,可能是多幕次富集成矿的产物;究其原因,前者是选择性富集的结果,受控于矿物组合及稀散金属的物理化学性质,而后者则是差异性富集的产物,受控于赋矿围岩岩性及控矿构造。(3)矿床中Cd、Tl与主成矿元素属同一成因,均表现出盆地卤水与油气流体混合成矿的特点。经重新估算,北厂和架崖山矿段的Cd、Tl资源量分别为159.2kt和7.1kt。结合区域资料综合分析,显示青藏高原北东-东南缘的西南三江成矿带上同类矿床均不同程度地富集Cd、Tl,具有重要的稀散金属资源潜力。The giant Jinding Zn-Pb deposit is characterized by abnormally rich concentrations of dispersed elements of Cd(176.2kt)and Tl(8.2kt),which account for 50.2%and 69.5%of the national total reserves(Cd 351kt,Tl 11.8kt),respectively.However,the spatial enrichment regularity of these two elements and their genetic relationship with the main ore-forming elements(e.g.,Pb,Zn and Fe)are still unclear,which limit the minerals exploration and resource evaluation.In this study,three-dimensional geological modeling and spatial analysis methods were used to investigate the spatial distribution and enrichment regularity of Cd and Tl at the main Beichang and Jiayashan ore blocks in the Jinding Zn-Pb deposit,aiming to elucidate the genetic correlation amongst them.The results show that Cd and Zn,Tl and Fe have similar spatial distribution characteristics.Both sandstone-and limestone-type orebodies are enriched in Cd and Tl,but the latter(mean metal content per unit volume Cd 0.341t,Tl 0.022t)has higher enrichment intensity than the former(Cd 0.141t,Tl 0.002t),and both concentrate in the extensional space of the hanging rocks above the thrust faults,with multiple concentrated centers,that are likely the products of multi-stage ore mineralization.The former is the result of selective enrichment,controlled by the mineral assemblage and the physicochemical properties of dispersed metals.Whilst the latter is the result of differential enrichment,controlled by ore-hosting lithologies and ore-controlling structures.Cd and Tl in the Jinding Zn-Pb deposit are the same origin as the main ore-forming elements,exhibiting an origin from the mixing process of the basinal brine and hydrocarbon-bearing fluid.After re-estimation,the resource reserves of Cd and Tl are reestimated to be 159.2 and 7.1 kilotons,respectively.Combined with regional data,it is shown that many similar deposits along the Sanjiang metallogenic belt in the northeastern and southeastern margins of the Qinghai-Xizang Plateau,are all enriched in Cd and Tl to varying degrees,wh

关 键 词：稀散金属 三维地质建模 空间分析 富集规律 金顶超大型Pb-Zn矿床 三江成矿带 

分 类 号：P612[天文地球—矿床学] P618.7[天文地球—地质学]