摘要
广西大厂矿田不但锡、锌、铅、锑等主要金属储量规模巨大,铟、锗、镉等稀散金属的经济价值也非常可观。本文系统收集整理了铜坑矿床资源勘查、开发过程中形成的1642个工程的编录资料,建立了三维空间数据库,对具有空间属性的Sn、Zn、Pb化学实验数据进行了统计分析。分析结果显示,相对92号矿体和细脉带矿体,91号矿体Sn、Zn品位高、富磁黄铁矿、主量金属相关性差,推测该矿体存在富含Sn、Zn的高温成矿流体叠加。岩浆期后热液型矿床随着远离含矿热液源头Zn/Pb值呈降低趋势,喷流沉积矿床随着距离喷口由近及远、沉积矿层由下往上,Zn/Pb值呈逐步增加趋势。铜坑矿床Zn/Pb空间分布规律是喷流沉积、岩浆热液叠加改造特征的复合,表明该矿床可能为喷流沉积-叠加改造复合成因。东岩墙(花岗斑岩脉)东西两侧随距离变远,Zn/Pb值呈近似对称性降低,推测东岩墙是成矿热液运移的通道。
The Dachang ore field in Guangxi Province has large reserves of main metals such as tin,zinc,lead and antimony,and accompanying some significant economic dispersed elements,e. g. indium,germanium and cadmium. The Tongkeng tin-indium polymetallic deposit is an important part of the Dachang ore field. The occurrence of ore bodies in Tongkeng deposit varied from bottom to top as stratiform → fine stockwork → big vine type. The bottom ore bodies show strong silicification, tourmalinization and feldspathization,and the top ore bodies have more sulphur-bearing saline minerals. The δ13 C and δ18 O values decrease with the increasing distances in ore surrounding rocks away from the orebodies from the lower part to the upper part. The δEu values show positive anomaly decrease with depth increasing in the ore bearing strata. A large number of bottom-up regularity characteristics indicate that the evolution of ore-forming fluid has spatial regularity. In this paper,we collected and sorted out 1642 projects of Tongkeng deposit resources exploring and mining,and established a 3 D spatial database,grade data of Sn,Zn and Pb were assigned space attributes and analysized. Based on analysis results,compared with No. 92 ore body and veinlet belt ore body,No. 91 ore body has high Sn and Zn grades,poor correlation between magnetite rich pyrite and major metals. It is speculated that the ore body contains high temperature ore-forming fluids rich in Sn and Zn. The correlation of Sn,Pb and Zn in the veinlet belt ore body is better than other orebodies,indicating that the veinlet belt ore body has single mineralization process. The Zn/Pb value of the post magmatic hydrothermal deposits decrease with the distance from the source of ore bearing hydrothermal solution;and in SEDEX type deposits,the Zn/Pb value increase with the distance from the vent,and decrease from upper ore layer to lower ore layer. The spatial distribution of Zn/Pb in Tongkeng deposit shows a composite of exhalative sedimentation and magmatic hydrothermalism,which indicates that the deposit was formed by early exhalative sedimentation,and the late magmatic hydrothermal superimposition transformation. With the distance increasing eastward and westward from both sides of the east dyke( granite porphyry vein),the Zn/Pb values decrease approximately symmetrically. It is speculated that the east dyke is the channel of ore-forming hydrothermal migration. Due to the high enrichment of zinc near the east dyke,the dispersed elements,such as the indium,is also enriched. The prospecting work on both sides and deep part of the east dyke should pay more attention.
作者
燕永锋
贾福聚
杨光树
秦德先
陈爱兵
杨鸿飞
YAN YongFeng;JIA FuJu;YANG GuangShu;QIN DeXian;CHEN AiBing;YANG HongFei(Department of Earth Sciences,Kunming University of Science and Technology,Kunming 650093,China)
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2019年第11期3398-3406,共9页
Acta Petrologica Sinica
基金
国家重点研发计划项目(2017YFC0602500)
国家自然科学基金项目(41762008)联合资助
关键词
大数据
矿化规律
Zn/Pb
矿床成因
大厂矿田
Big data mining
Mineralization regularity
Zn/Pb
Deposit genesis
Dachang ore field
