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在内蒙古林西县西拉木伦断裂带内发育规模较大的中性岩墙群,岩墙多呈NE3°～5°近直立侵入.对岩石进行了锆石LA-ICP-MS U-Pb定年和详细的岩石地球化学特征研究.锆石LA-ICP-MS U-Pb年龄为132.2±2.2Ma,岩石侵位于早白垩世.岩石地球化学特征显示岩石具有高钾钙碱性系列-钾玄岩系列的过渡特征,形成于板内拉张环境,岩浆源区具有壳幔混源的特征,是早期俯冲洋壳遭受幔源岩浆底侵作用的结果.岩墙的产状受左旋剪切机制控制,该机制可能主要与太平洋板块相对亚洲板块的向北运动有关.
Large-scale neutral dyke swarms developed in the West Lamelun fault zone of Linxi County, Inner Mongolia, with almost vertical eruptions of NE3 ° ~5 °. The zircon LA-ICP-MS U-Pb Dating and detailed lithogeochemical characteristics of the rocks.The U-Pb dating of LA-ICP-MS was 132.2 ± 2.2Ma and the rocks intruded in the Early Cretaceous.The geochemical characteristics of rocks show that the rocks have a series of high-K calc-alkaline The transitional features of the rock series are formed in the plate extensional environment and the magmatic source region has the characteristics of crust-mantle mixed source, which is the result of mantle-derived magmatic underplating in the early subducted oceanic crust. This mechanism may be mainly related to the northward movement of the Pacific plate relative to the Asian plate.