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分析隐伏逆冲构造变形特征,揭示构造形成机制,开展构造预测,指导煤地质勘查。通过地表精细观测、二维地震勘探及钻探工程验证等综合方法,在发现并了解其形态学特征基础上,分析表层构造与深部构造耦合关系,结合古构造应力场,阐述构造成因。结果发现南北向深部隐伏逆冲构造,西倾东冲,断面倾角为20°~35°,断于石盒子组内和下伏含煤岩系及其基底内,地层垂直断距为190~260 m,水平断距260~470 m;浅部地层表现为同向展布的不对称背斜构造,二者空间上密切共生,几何学和运动学具相关性,成因上具统一性;浅层背斜构造是深层逆冲作用控制下断展褶皱作用的结果。隐伏逆冲构造是燕山运动中期盆地内部因阻抗来自东侧构造挤压应力,而产生的反向逆冲构造作用响应。该逆冲构造错断煤层,造成煤层重复,控制了煤层的空间分布,构成韩城矿区南中深部重要的构造边界。
Analyzes the deformation characteristics of the hidden thrust structure, reveals the tectonic formation mechanism, carries out the tectonic prediction and directs the coal geological prospecting. Based on comprehensive analysis of surface subtle observation, 2D seismic exploration and drilling engineering verification, the paper analyzes and analyzes the morphological characteristics and analyzes the coupling relationship between surface structure and deep structure. Based on the palaeotectonic stress field, the cause of formation is expounded. The results show that the north-south depression is a deep concealed thrust structure with a westward dip and eastward dip with a dip angle of 20 ° ~ 35 °, which is located within the Shixianzi Formation and underlying coal-bearing rock series and its basement. The vertical fault spacing is 190-260 m, with a horizontal fault interval of 260-470 m. The shallow strata show an asymmetrical anticlinal anticline structure with the same distribution. The two are closely co-occurring in space and are related to geometry and kinematics. The shallow layers The anticline structure is the result of the extensional fold under the control of deep thrusting. Hidden thrust structure is the response of the reverse thrust produced by the crustal compressive stress in the mid-Yanshanian basin due to the impedance. The thrust structure breaks the coal seam, causing the coal seam to repeat and control the spatial distribution of the coal seam, forming an important structural boundary in the deep south-central part of the Hancheng mining area.