投稿时间：2014-06-12
修订日期：2015-07-01
网络发布日期：2015-10-29
中文摘要:雄村矿区位于西藏冈底斯斑岩铜矿带西段,目前在该矿区发现了Ⅰ、Ⅱ、Ⅲ号斑岩型铜金矿体。文章通过Ⅱ号矿体硫、铅同位素研究,获得Ⅱ号矿体金属硫化物的δ34S值为-1.6‰～-0.6‰,平均值-1.30‰,总硫同位素值(δ34SΣS)为0.99‰,与含矿斑岩的硫同位素组成(-2.1‰～＋1‰,平均0.06‰)一致,均落入幔源硫范围,表明硫主要来自岩浆。含矿斑岩和金属硫化物的铅同位素组成206Pb/204Pb、207Pb/204Pb、208Pb/204Pb分别为18.460～18.560、15.586～15.622、38.603～38.727和17.972～18.425、15.528～15.593、38.024～38.489,两者的铅同位素组成基本一致,变化范围小,表明两者具有相同的来源。所有样品的铅同位素μ值为9.34～9.49,显示幔源特征,综合源区判别图解认为铅主要来源于幔源,有少量俯冲沉积物加入,矿床形成于与洋壳俯冲消减作用有关的岛弧构造环境。
Abstract:The Xiongcun district, located in the western segment of the Gangdese porphyry copper belt (GPCB), hosts the only known Jurassic mineralization area in the GPCB, Tibet, PRC. Three porphyry copper-gold deposits (No.Ⅰ, No.Ⅱ and No.Ⅲ) have been discovered in the Xiongcun district. This paper focuses on the sulfur and lead isotopes research of the No.Ⅱ deposit. S isotopic composition of ore sulfides similar to those of the ore-bearing porphyry. The δ34S values of ore sulfides vary from -1.6‰ to -0.6‰ with an average value of -1.30‰, δ34SΣS value is 0.99‰, and the δ34S values of the ore-bearing porphyries vary from -2.1‰ to +1‰ with an average value of 0.06‰, indicating that sulfur is mainly derived from the magma of porphyry. Lead isotopes of 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb from ore-bearing porphyry vary from 18.460 to 18.560, 15.586 to 15.622, 38.603 to 38.727, respectively, and those from ore sulfides vary from 17.972 to 18.425, 15.528 to 15.593, 38.024 to 38.489, respectively. The uniform of Pb isotopic compositions of ore-sulfides and ore-bearing porphyry from the deposit implies that their Pb could be derived from the same source.The μ values (9.34～9.49) and the source distingu ishing diagram of the lead isotopic compositions of ore-sulfides and ore-bearing porphyry indicate that the leadcould be derived from a mantle source with minor contamination of subducted sediments and the deposit formed in the island arc setting related to northward subduction of the Neo-Tethys oceanic slab.
keywords:geochemistry sulfur isotope lead isotope ore-forming material sources island arc Xiongcun Tibet
文章编号：
中图分类号：P618.41;P618.51
文献标志码：
基金项目:本研究得到自然科学基金项目(编号:41172077、41502079)、四川省教育厅自然科学重点项目(编号:15ZA0073)、四川省青年基金项目(编号:2014JQ0047)、地调项目(编号:03-002-0557、资[2014]01-028-042)、“973”项目(编号:2011CB403103)、四川省矿产资源研究中心项目(编号:SCKCZY2013-YB006)和"构造成矿学理论发展与实践"项目(编号:13TD0008)联合资助
引用文本：
尹青,郎兴海,唐菊兴,张金树,谢富伟,杨宗耀,李志军,黄勇,白云,付红超.2015.西藏雄村矿区Ⅱ号矿体硫、铅同位素地球化学特征[J].矿床地质,34(5):1016~1029YIN Qing,LANG XingHai,TANG JuXing,ZHANG JinShu,XIE FuWei,YANG ZongYao,LI ZhiJun,HUANG Yong,BAI Yun,FU HongChao.2015.Geochemical characteristics of sulfur and lead isotopes from No.Ⅱ deposit in Xiongcun district, Tibet[J].Mineral Deposits34(5):1016~1029
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