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现代地质 ›› 2012, Vol. 26 ›› Issue (3): 445-452.

• 矿床学与构造学 • 上一篇    下一篇

云南格咱岛弧岩浆成矿带铅同位素特征及成矿物质来源示踪

 刘学龙1,2, 李文昌1,2, 尹光侯2   

  1. 1 中国地质大学 地球科学与资源学院,北京100083;2 云南省地质调查局,云南  昆明650051
  • 收稿日期:2011-11-28 修回日期:2012-01-25 出版日期:2012-06-07 发布日期:2012-06-14
  • 通讯作者: 李文昌,男,教授,博士生导师,1962年出生,矿床学专业,主要从事云南省地质矿产勘查与研究工作。Email:lwenchangynddy@163.com。
  • 作者简介:刘学龙,男,博士研究生,1983年出生,矿床学专业,主要从事云南“三江”地区的地质矿产研究工作。Email:xuelongliu@foxmail.com。
  • 基金资助:

    国家重点基础研究发展计划项目(“973”课题)“巨型矿床的变化与保存”(2009CB421007);中央高校基本科研业务费专项资金项目“云南中甸格咱岛弧斑岩成矿系统研究”(2011PY0154);中国地质调查局国土资源大调查项目“滇西北地区斑岩成矿系统研究与靶区优选”。

Lead Isotope Characteristics and Tracing Significance of Ore MetallogenicMaterial in Geza Arc Metallogenic Belt,Yunnan

 LIU  Hua-Long-1,2, LI  Wen-Chang-1,2, YIN  Guang-Hou-2   

  1. 1 School of Earth Sciences and Resources, China University of Geosciences, Beijing100083,China;2 Yunnan Geological Survey, Kunming,Yunnan650051,China
  • Received:2011-11-28 Revised:2012-01-25 Online:2012-06-07 Published:2012-06-14

摘要:

云南格咱岛弧成矿带是西南三江构造岩浆岩带的重要组成部分,是我国近年来新发现的铜多金属矿集区,产出有普朗超大型斑岩型铜矿、雪鸡坪中型斑岩型铜矿、红山大型矽卡岩-斑岩型铜矿等。测试结果表明,典型成矿斑岩体的矿石矿物铅同位素组成:206Pb/204Pb为 17.680~19.165, 207Pb/204Pb 为15.453~15.773,208Pb/204Pb为37.730~39.654,铅同位素组成较为稳定,具有贫铀铅、富钍铅的特征。铅同位素组成与特征参数(Δβ与Δγ、V1与 V2)之间具有明显的正相关性,依据铅构造模式判别和成因分类的综合分析,格咱岛弧成矿带的铅主要来源于地幔和下地壳,具壳幔混合来源的特征,其成矿作用与岩浆岩活动存在较为密切的关系。

关键词: 岛弧成矿带, 铅同位素, 成矿物质来源, 格咱, 云南

Abstract:

Geza arc is an important part of Yidun island arc in the southwest Sanjiang tectonic magmatic belts, located in the southern tip of the Yidun island arc, newly discovered copper polymetallic ore concentration area of China in recent years, in which Pulang super large sized porphyry copper deposits, Xuejiping medium sized porphyry copper deposits, Hongshan large sized skarn porphyry copper deposits occur.The lead isotopic compositions of ore mineral,with 206Pb/204Pb ranging from 17.680 to 19.165,207Pb/204Pb ranging from 15.453 to 15.773,208Pb/204Pb ranging from 37.730 to 39.654,was relatively stable and charactered by depleted uranium, rich thorium. There was a significant positive correlation between lead isotopic composition and characteristic parameters (Δβ and Δγ, V1 and V2). Based on the lead structural pattern recognition and the original classification of comprehensive analysis, the lead isotope of Geza island arc metallogenic belt is mainly derived from the mantle and the lower crust, with the crustmantle mixed source characteristics. The mineralization is closely related with magmatic activities.

Key words: arc metallogenic belt, lead isotope, metallogenic material source, Geza, Yunnan