陕西马元铅锌矿S、Pb同位素地球化学特征及成矿物质来源探讨  

Discussion of ore-forming material source and sulfur and lead isotopic geochemistry of Mayuan Pb-Zn deposit in Shaanxi

作　　者：王海[1,2] 王京彬[2] 祝新友[2] 程细音[2] 蒋斌斌[2] 

机构地区：[1]昆明理工大学,云南昆明650093 [2]北京矿产地质研究院,北京100012

出　　处：《矿产与地质》2017年第2期241-247,共7页Mineral Resources and Geology

基　　金：中国地质调查局地质调查工作项目<广东省梅州市玉水铜矿接替资源勘查项目>(2013-01-036-051);<老矿山典型矿床成矿规律总结研究>(12120113086300;12120113086400;12120114092601;12120114092501)共同资助

摘　　要：马元铅锌矿床位于扬子板块北缘碑坝穹窿构造的南缘,是区域上重要的碳酸岩型铅锌矿,矿体赋存于震旦系灯影组白云岩中。通过对马元铅锌矿床中矿石矿物闪锌矿、方铅矿和黄铁矿的硫、铅同位素系统研究,探讨其成矿物质来源。研究表明:马元铅锌矿床中矿石矿物的δ^(34)S值为15.4‰~19.6‰,平均为17.67‰,重晶石的δ^(34)S值为33.2%~33.5%,平均为33.3%,显示S主要形成于海相硫酸盐的热化学还原作用;矿石矿物的^(206)Pb/^(204)Pb值、^(207)Pb/^(204)Pb值和^(208)Pb/^(204)Pb值分别为17.62%~18.02%、15.49%~15.65%和37.57%~38.35%,组成较为均一,Pb主要来自于壳幔混合的造山带,基底岩系可能是马元铅锌矿床成矿物质的重要来源。Mayuan Pb-Zn ore deposit,located in the southern margin of the Beiba dome structure in the northern part of Yangtze Platform,is the important carbonate-type Pb-Zn deposit in the region.The orebodies are hosted in the dolomite of Sinian Dengying Formation.The sulfur and lead isotopic features are systematically studied for sulfide minerals,including sphalerite,galena,and pyrite of the deposit in order to analyze the ore-forming material source.The research result indicates that the δ^（34）S value of the ore minerals varies from 15.4%to 19.6% with the average value of 17.67%,and that of barite varies from 33.2%to 33.5%,with the average value of 33.3%.It shows that the sulfur is mainly derived from thermo-chemical reduction（TSR）of marine sulfate.The ^（206）Pb/^（204）Pb ratio,^（207）Pb/^（204）Pb ratio and ^（208）Pb/^（204）Pb ratio are respectively 17.62%-18.02%,15.49%-15.65% and 37.57%-38.35% with even constitution.Pb is mainly derived from the orogenic belt of crust-mantle mixing source.And Pb-Zn-rich basement strata might be the important source of ore-forming materials.

关 键 词：马元铅锌矿 硫铅同位素 地球化学特征 成矿物质来源 陕西 

分 类 号：P618.4[天文地球—矿床学] P595[天文地球—地质学]