摘要:贺兰山构造带位于鄂尔多斯盆地与阿拉善地块之间，经历了元古代以来长期的构造演化过程。贺兰构造带北段的桌子山具有复杂的构造样式，该构造样式记录了鄂尔多斯块体、阿拉善块体以及古亚洲洋构造演化的丰富信息。详细的野外构造解析揭示，贺兰构造带北段桌子山地区自中生代以来主要经历了多期挤压构造变形。第一期构造变形以三叠系及其以下地层中的NWW向宽缓褶皱为代表，指示了晚三叠纪NNE向的挤压作用；第二期以侏罗系及其以下地层中的NE走向构造为代表，指示了晚侏罗世NW向的挤压作用；第三期构造变形以黄河断裂发生右旋走滑及其两侧早期变形构造线走向及古应力场方向之间30°夹角差异为代表。黄河断裂以东白垩系及其以上地层结构稳定，结合前人古地磁研究结果，认为第三期构造变形为桌子山沿黄河断裂发生近30°逆时针旋转，变形时间为新生代。
关键词: 构造解析/
桌子山/
贺兰山构造带/
阿拉善块体/
鄂尔多斯盆地
Abstract:The Helanshan tectonic belt is located between the Alax massif and the Ordos Basin, and underwent multi-stage deformation from Proterozoic. The Zhuozishan Mountain in the northern of the Helanshan tectonic belt contained a complex structural style, and which recorded the abundant information on the evolution of the Alax massif, the Ordos Basin and the Paleo Asian Ocean. After a detailed outfield structural analyses, an outcome was get that the Zhuozishan Mountain underwent multi-stage of the deformation during the Mesozoic and Cenozoic. The first one was characterized by the NWW-trending folds formed in Triassic and the Pre-Triassic strata, indicating a NNE-direction compression in the Late Triassic. The second one was characterized by the NE-trending structures formed in the Jurassic and the Pre-Jurassic strata, indicating a NW-direction compression in the Late Jurassic. The third phase of the deformation was characterized by the dextral slip of the Huanghe fault and the 30° direction discrepancy of the earlier structures and paleostress field distributed in the both sides of the Huanghe fault. As the Cretaceous and the upper strata in the east of the Huanghe fault were stable as well as the previous paleomagnetism results, the third phase of the deformation was confined as the 30° anticlockwise rotation of the Ordos massif along the Huanghe fault in the Cenozoic.
Key words:?Structural analyses/
Zhuozishan Mountain/
Helanshan tectonic belt/
Alax massif/
Ordos Basin
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