鄂尔多斯盆地东缘中—新生代构造特征及构造应力场分析

    Structural features and tectonic stress fields of the Mesozoic and Cenozoic in the eastern margin of the Ordos basin, China

    • 摘要: 对鄂尔多斯盆地东缘黄河沿岸一带中—新生代构造特征的研究表明:盆地东缘中—新生代构造变形与印支运动、燕山运动、喜马拉雅运动密切相关。印支运动对东缘构造影响相对微弱,受扬子板块和华北板块碰撞的影响,区内形成了一套挤压应力近NS向的共轭节理。燕山运动对东缘的形成演化意义重大,其基本构造形态就是在这一时期形成的。受古太平洋板块与亚洲大陆俯冲产生的远程构造效应的影响,区内发育NE—NNE走向的褶皱带;离石断裂受到SE—SEE方向的挤压,以脆性变形为主;节理解析获得的燕山期构造应力场以NW—SE向挤压为特征。喜马拉雅运动期间,盆地东缘的挤压方向转变为NE—SW向,其动力主要来自印度板块向欧亚板块的碰撞及碰撞期后陆内俯冲所产生的远程效应。

       

      Abstract: The structural features of the Mesozoic and Cenozoic in the eastern margin of the Ordos basin were studied. The results indicate that this field had influenced by the Indosinian movement, Yanshanian movement and Himalayan movement in Mesozoic and Cenozoic. The direction of tectonic stress field is nearly NS during the Indosinian movement, which is basically resulted from the collision between the Yangtze plate and the North China plate. During the Yanshanian movement, the structural styles of the eastern margin of Ordos basin were basically formed. As a result of far-field effects produced by subduction of the Paleo-Pacific plate beneath the Asian continent, a series of open gentle superficial folds stroke NE-NNE were developed in this field and Lishi fault was compressed from SE-SEE and characterized brittle deformation. During the Himalayan movement, the stress direction becomes NE-SW, and this is a result of far-field effects produced by the collision between the Indian plate and the Eurasian plate.

       

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