张小强;魏启荣;魏俊浩;孙骥;郝伟;张德才;

• 1:中国地质大学资源学院
• 2:内蒙古自治区第二地质矿产勘查开发院

摘要(Abstract)：

内蒙古基东地区辉长岩体位于北山成矿带北侧的石板井-七一山-呼伦西伯成矿带西北缘。该辉长岩体的岩石类型主要为辉长岩,次为角闪辉长岩,少量为辉长闪长岩。对辉长岩体进行了LA-ICP-MS锆石U-Pb测年以及主微量元素等分析。研究结果显示:辉长岩体形成于晚泥盆世(D3),其LA-ICP-MS锆石U-Pb年龄为(371.3±2.0)Ma。辉长岩体主量元素表现出富Al[w(Al2O3)=17.94%～20.93%]、高Na[w(Na2O)=2.08%～3.75%]和低K[w(K2O)=0.16%～0.98%]的岩石地球化学特征,属钙碱性系列。稀土元素配分模式为LREE富集的右倾型,其(La/Yb)N比值为1.92～4.62,无铈异常(Ce/Ce*=1.00～1.11),部分具正Eu异常(Eu/Eu*=1.08～2.20)。微量元素比值蛛网图表现出P、Ti的亏损和Sr的富集。辉长岩体形成于岩浆弧环境,属白山晚古生代岩浆弧的组成部分,是红石山大洋向南俯冲所形成的岩浆产物。

关键词(KeyWords)： 辉长岩体;岩石地球化学;锆石U-Pb定年;构造环境;内蒙古基东

Abstract:

Keywords:

基金项目(Foundation): 内蒙古自治区国土资源厅项目“内蒙古额济纳旗基东等4幅1∶5万区域矿产地质调查”(2009020008)

作者(Author): 张小强;魏启荣;魏俊浩;孙骥;郝伟;张德才;

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