西藏洞中拉铅锌矿床S、Pb同位素组成对成矿物质来源的示踪  

SULFUR AND LEAD ISOTOPE COMPOSITION TRACING FOR THE SOURCES OF ORE-FORMING MATERIAL IN DONGZHONGLA PB-ZN DEPOSIT,TIBET

作　　者：闫国强[1] 钟康惠[1] 白景国 王欣欣[3] 杨红英 刘珂辛[1] 

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]四川有色冶金地质勘察院,四川成都610059 [3]成都理工大学沉积地质研究院,四川成都610059 [4]中铁二院地勘岩土公司,四川成都610059

出　　处：《甘肃地质》2011年第2期35-39,65,共6页Gansu Geology

基　　金："十一五"国家科技支撑计划项目子课题:冈底斯东段铜多金属矿床时空关系和叠加改造研究(2006BAB01A04-4)

摘　　要：西藏洞中拉铅锌矿床位于冈底斯成矿带东段北亚段,矿体发育于上石炭统—下二叠统来菇组灰岩—大理岩化灰岩内的矽卡岩中。在分析该矿床成矿地质背景及对矿区控矿构造分析的基础上,对比前人数据较为系统的研究了矿石S、Pb同位素组成,探讨了成矿物质的来源。表明矿区矿石硫同位素分布范围较窄,呈塔式分布,总硫同位素值约为5.21‰,具有岩浆硫的特征;矿石铅同位素组成稳定,为正常普通铅,矿石铅来源于单阶段模式年龄约为131～134Ma的晚燕山早期上地壳熔融形成的岩浆。Dongzhongla lead-zinc deposit in Tibet is located in the north sub-zone of eastern section of Gangdise metallogenic belt.The ore body mainly occurs as stratoid form in the skarn and skarnization marble of the Middle Carboniferous-Upper Permian Laigu Formation.Based on analysis of the ore-forming geological backgrounds and structure of ore,the paper studied systematically the composition characteristics of S and Pb isotopes in the ore,and discussed the sources of the ore-forming materials.The studies show that the composition of S isotope in ore sulfides confined in a narrow variation range.The value of total 34S is 5.21‰,which present a characteristic of sulfur from magmatic origin.The Pb isotopic composition of ore sulfides is stable and the ore lead is ordinary common lead.Ore lead derived from magma,which came from partial melting of the upper crust in Early period of later-Yanshan and its pattern-age is about 131～134Ma.

关 键 词：来源示踪 成矿物质 硫、铅同位素组成 洞中拉铅锌矿床 西藏 

分 类 号：P597.2[天文地球—地球化学]