大兴安岭南段多金属成矿带硫、铅同位素组成及其地质意义  

Sulfur and Lead Isotopic Compositions of the Polymetallic Deposits in the Southern Daxing'anling: Implications for Metal Sources

作　　者：要梅娟[1,2] 刘家军[1,2] 翟德高[1,2] 王建平[1,2] 邢永亮[1,2] 

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]中国地质大学地球科学与资源学院,北京100083

出　　处：《吉林大学学报（地球科学版）》2012年第2期362-373,共12页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金重点项目(41030423);国家自然科学基金项目(40973035);国家重点基础研究发展规划项目(2006CB403500);高等学校学科创新引智计划项目(B07011)

摘　　要：大兴安岭南段是我国北方重要的多金属矿床成矿带,对其成矿物质来源的分析研究有利于区域成矿规律的总结。在前人的工作基础上,对典型矿床的矿石矿物进行了硫、铅同位素研究。结果表明:闪锌矿、方铅矿、毒砂、黄铜矿、辉钼矿等硫化物的δ34S值主要变化范围为-6‰～4‰,平均值为0‰,峰值出现在0‰～2‰,呈塔式分布;无明显的重硫、轻硫富集,说明硫源较单一;矿石矿物及岩石的206 Pb/204 Pb、207Pb/204Pb、208Pb/204Pb值的变化范围主要集中在18.13～18.74、15.38～15.68和37.1～38.93,其平均值分别为18.38、15.54和38.09。同时,数据结果显示:成矿带的东部与西部存在较为明显的铅同位素差异,西部矿床中铅的分布主要集中在造山带演化线附近,而东部矿床中铅主要集中分布在上地幔和造山带演化曲线附近。The southern Daxing＇anling,where tens polymetallic deposits lie,is one of important metallogenic zones in Northern area of China.Lead and sulfur isotope geochemistry is helpful for determining the sources of ore-forming materials.On the basis of predecessors＇ research,sulfur and lead isotopic characteristics of sulfides from some polymetallic deposits have been studied in this paper.The δ34S values of sphalerite,galena,arsenopyrite,chalcopyrite,and molybdenite rang from-6‰ to ＋4‰,with mean value of zero.The δ34S values of most sulfides range from 0 to 2 ‰ with a pronounced tower effect,and without significant enrichment in the light sulfur and heavy sulfur,which suggests that the sulfur source is single and dominated by magmatic sulfur.Ratio values of lead isotope in both sulfides and related rocks range from 18.13 to 18.74 for 206Pb/204Pb,15.38 to 15.68 for 207Pb/204Pb,and 37.1 to 38.93 for 208Pb/204Pb.Their mean values are 18.38,15.54 and 38.09,respectively.Lead isotopic compositions also show obvious differences between the western and the eastern part in the southern Daxing＇anling.In the lead isotopic compositions diagram,samples from polymetallic deposits in the western part are scattered nearby the evolution curve orogenic belts,while those from deposits in the eastern part are nearby curves of the orogenic belt and the upper mantle.

关 键 词：多金属成矿带 硫、铅同位素组成 地质意义 大兴安岭南段 金属矿床 

分 类 号：P618.4[天文地球—矿床学]