滇西沧源铅锌多金属矿集区成矿地球化学特征  

Metallogenic geochemistrycharacteristics of the lead- zinc polymetallic mineralization concentration area in Cangyuan,western Yunnan.

作　　者：肖晓牛[1] 喻学惠[1] 杨贵来[1,2] 杨伟光 莫宣学[1] 曾普胜 

机构地区：[1]中国地质大学(北京) 地质过程与矿产资源国家重点实验室及岩石圈构造、深部过程及探测技术教育部重点实验室,北京100083 [2]云南省地矿资源股份有限公司,昆明650215 [3]云南省财贸大学,昆明650221

出　　处：《岩石学报》2008年第3期589-599,共11页Acta Petrologica Sinica

基　　金：国家重点基础研究发展规划项目(编号:2002CB412603);云南省地矿资源股份有限公司资助

摘　　要：滇西沧源铅锌多金属矿集区位于中缅边境的金腊-金厂一带,是云南省地矿资源股份有限公司新近开发的一个资源产地。本文重点提供了流体包裹体中稀土微量元素和矿石的 S、Pb 同位素的分析结果,并对成矿流体性质,成矿物质来源等进行了讨论。研究表明,本区流体包裹体中∑REE 变化较大,在0.371～212.1×10^(-9)之间。反映轻重稀土分馏程度的LREE/HREE 比值和(La/Yb)_N 比值变化也比较大,分别落在1.23～31.47和2.87～505之间。矿石的硫同位素除一个重晶石的δ^(34)S 偏高,达20.8～22.1‰,其它硫化物的δ^(34)S 均落在-0.6～5.1‰范围内,具幔源硫值特征。矿石的铅同位素^(208)Pb/^(204)Pb、^(207)pb/^(204)Pb 和^(206)Pb/^(204)Pb 分别变化在38.621～38.993,15.584～15.738和18.568～18.800之间,不同矿段、不同硫化物矿物(方铅矿、闪锌矿、黄铁矿、辉锑矿)之间,Pb 同位素组成范围非常相近,表明研究区各矿段,铅的来源和成因是均一的、相同的,而且具有造山带 Pb 同位素特征。结合区域成矿地质背景及流体包裹体 C、H、O 同位素研究结果,推测本区成矿流体是以浅部流体为主,并有深源流体参与的一种混合流体。矿石 S、Pb 同位素组成表明,成矿物质也具有壳幔混合源的特征。The lead-zinc polymetallic mineralization concentration area of CangYuan, Weatern Yunnan located in Jinchan-Jinla near the border of China and Burma, and is a new resource district that is explored recently by Yunnan Geology ＆ Mineral Resources Co. LTD. Based on the studies on trace elements in fluid inclusions and geochemistry of S, Pb isotopes of ore, the characteristics of ore- forming fluid and the metallogeneses of deposits have been discussed. The results show the large ∑ REE, LREE/HREE and（La/Yb） N variation from 0. 371 to 212. 1 × 10^-9, from 1.23 to 31.47, from 2. 87 to 505, respectively. Most otherb＂34 S range from - 0. 6 to 5. 1‰, except for one barite with higher range of 20. 8 - 22. 1‰, this indicates that the sulfide of ore was mainly derived from the mantle. The ^208pb/^204pb,^207pb/^204Pb and ^206pb/^204Pb values of ore range from 38. 621to 38. 993, from 15. 584 to 15.738, from 18. 568 to 18. 800, respectively. There are no obvious difference in the lead isotopic composition from different ore blocks and different sulfide （galena, pyrite, sphalerite, stibnite） , these characteristics indicate that they have the homogeneous, same source and geneses of Pb, and the lead is of characteristics of orogenic belt lead. In combination with the regional metallogenic setting and the previous analytical results of C, H, O isotope of the fluid inclusions, it may be concluded that the mineralization fluid belong to a mixed origin of mainly shallow-seated fluid and minor plutonic fluid. S, Pb isotopic composition of ore also suggest that ore-forming materials were from the mantle with some shallow-seated source.

关 键 词：铅锌多金属矿 稀土微量元素 硫 铅同住素 滇西沧源 

分 类 号：P611[天文地球—矿床学] P612[天文地球—地质学]