新疆阿尔泰造山带库卫基性侵入岩形成时代及地质意义  

The Formation Age of Kuwei Mafic Pluton and its Geological Significance in Altay Orogen,Xinjiang

作　　者：周刚[1] 董连慧[1] 秦纪华[2] 张立武[2] 贺永康[3] 赵忠合[2] 雷永孝[3] 

机构地区：[1]新疆维吾尔自治区地质矿产勘查开发局,新疆乌鲁木齐830000 [2]新疆维吾尔自治区地质矿产勘查开发局第四地质大队,新疆阿勒泰836500 [3]西安地质矿产研究所,陕西西安710054

出　　处：《新疆地质》2014年第3期283-288,共6页Xinjiang Geology

摘　　要：库卫岩体主要由橄榄辉长岩、辉长岩、角闪辉长岩及斜长角闪岩组成。岩体稀土元素含量低,∑REE值为9.97×10-6~26.43×10-6,角闪辉长岩（La/Yb）N值为1.77~1.83,铕的正异常弱;橄榄辉长岩（La/Yb）N值为3.07~4.42,具明显的正铕异常。岩体不相容元素含量低,具明显的Sr,Rb,K正异常和Nb,Ta负异常,没有明显的P,Ti异常。岩体La-ICP-MS锆石U-Pb年龄为（381.2±2.8）Ma,形成于陆缘弧环境。岩浆主要来自于亏损地幔,可能受俯冲板片流体的交代。The Kuwei pluton is made up of olivine gabbro,gabbro,homblende gabbro and plagioclase amphibolite.The pluton REE content is quite low, so that its ∑ REE changes only between 9.97 × 106-26.43 × 10^-6.The （La/Yb）N of horn blende gabbro reaches 1.77-1.83 with the weakly positive Eu anomaly.The （La/Yb）N of olivine gabbro reaches 3.07- 4.42 with the obviously positive Eu anomaly.The content of incompatible elements is quite low, and with the Sr, Rb,K positive anomaly, Nb,Ta negative anomaly without P, Ti obviously anomaly.Zircon La-ICP-MS U-Pb age of this pluton is （381.2±2.8） Ma,and formed in continental margin arc environment.The magma is mainly from the depleted-mantle,and it maybe affected by slab fluids explanation.

关 键 词：库卫 基性侵入岩 形成时代 

分 类 号：P588.12[天文地球—岩石学]