孔会磊;李金超;栗亚芝;贾群子;杨宝荣;

• 1:中国地质调查局西安地质调查中心
• 2:青海省有色地质矿产勘查局八队

摘要(Abstract)：

对产于东昆仑成矿带东段的按纳格闪长岩体进行的岩石学和地球化学研究及锆石LA-ICP-MS U-Pb法定年研究表明:该岩体的成岩年龄为(474.1±2.4)Ma,形成时代为早奥陶世,属加里东期;其w(SiO2)为52.63%~56.56%,具贫K2O(0.41%~0.73%),富CaO(7.23%~9.17%)、Na2O(2.62%~4.67%)的特点,为钙碱性-低钾(拉斑)系列准铝质岩石。岩石明显富集大离子亲石元素(如Ba)、LREE和活泼的不相容元素(如U、Th),相对亏损高场强元素(如Nb、Zr、Hf、Ti、P)。稀土元素总量变化不大(130.09×10-6~182.76×10-6),显示了轻稀土元素强烈富集的右倾式稀土元素配分型式。δEu变化范围为0.81~0.89,具有弱的负铕异常。Rb/Sr、Nb/Ta等特征反映出岩石具幔源岩浆的特点,亦显示岩浆受到地壳物质的混染。构造环境判别图解显示按纳格闪长岩形成的大地构造背景为洋壳俯冲造山阶段的岛弧环境。

关键词(KeyWords)： 地球化学;锆石LA-ICP-MS U-Pb测年;构造背景;按纳格闪长岩;东昆仑

Abstract:

Keywords:

基金项目(Foundation): 中国地质调查局地质大调查项目“青海省地质调查综合研究”(1212010918044);“柴达木周缘及邻区成矿带与整装勘查区地质矿产调查综合研究”(12120113029000)

作者(Author): 孔会磊;李金超;栗亚芝;贾群子;杨宝荣;

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DOI:

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