内蒙古地区聚煤规律、赋煤构造格局的基本特征

Basic characteristics of coal accumulation law and occurrence tectonic pattern in Inner Mongolia

以占内蒙古煤炭资源99%的7个煤炭勘查区域的勘查资料为基础,研究内蒙古地区赋煤特点。从内蒙古地区地层、构造地质历史时期的阶段性特点、主要成煤时期聚煤特征和赋煤构造单元划分方面,分析了在经历海西、印支、燕山和喜马拉雅运动后,不同时期、不同区域大地构造历史事件下,内蒙古地区石炭—二叠世、早—中侏罗世、早白垩世3个主要成煤时期典型盆地在不同沉积层序期和不同沉积体系下聚煤特点;以及该地区3个一级赋煤构造单元(赋煤构造区),11个二级赋煤构造单元(赋煤构造带)的构造特征,同时介绍了不同赋煤构造带内煤矿或煤产地煤炭产出比例以及主要含煤地层情况。通过分析研究总结出内蒙古地区聚煤、赋煤构造在空间上的分布特点,说明了受到多次构造运动影响,聚煤盆地的形态和位置发生不同程度的变化。东北赋煤构造区内聚煤盆地类型主要为断陷型,受盆缘主干断裂控制NE—NNE向展布。华北赋煤构造区总体呈不对称的环带结构,北部阴山地区以近E—W向控煤构造为主,西缘挤压带以多条近N—W走向的逆冲断裂构造为主,南部简单的单斜构造控制且断裂不发育。西北赋煤构造带以早—中侏罗世特大型聚煤盆地为主,受后期构造运动的改造,盆地周缘构造较复杂,断裂发育,地层倾角较大,盆地内部为宽缓的褶曲构造,倾角变缓。以构造作用为研究核心,揭示含煤盆地构造演化形成的特定沉积体系、含煤岩系后期改造和煤炭资源的聚集和赋存规律,推演出古环境下该地区不同成煤时期控煤特征。

Based on the exploration data of seven coal exploration areas which accounting for 99%of Inner Mongolia’s coal resources,the characteristics of coal occurrence in Inner Mongolia was investigated in this study.From the strata of Inner Mongolia,the stage characteristics of structural geology in historical period,the characteristics of coal accumulation in main coal forming period and the division of coal occurrence tectonic units,the coal accumulation characteristics of three typical basins in the Carboniferous-Permian,early Middle Jurassic and early Cretaceous in different sedimentary sequences and systems in Inner Mongolia were analyzed at different periods and areas in the historical events of geo-tectonics,i.e.,the Hercynian,Indosinian,Yanshanian and Himalayan movement.Also,the tectonic characteristics of three primary coal occurrence tectonic units(coal occurrence tectonic areas)and eleven secondary coal occurrence tectonic units(coal occurrence tectonic belts)were analyzed.The coal production proportion and main coal bearing strata of coal mines or coal producing places in different coal occurrence tectonic belts were introduced.Through analysis and research,the spatial distribution characteristics of coal accumulation and coal occurrence tectonics in Inner Mongolia were summarized.It shows that the coal accumulation is influenced by multiple tectonic movements,and the shape and location of coal accumulating basins change to different degrees.The main types of coal accumulating basins in the northeast coal occurrence tectonic areas are faulted type.Controlled by the main fracture of basin margin,it spreads in NE-NNE direction.The north coal occurrence tectonic areas are in an asymmetric banded structure,and the North Yinshan area is dominated by the coal control structure in the direction of near E-W,and the West margin extrusion belt is dominated by a number of thrust faults structure in the N-W direction,and the South is simple monoclinal structure controlled and undeveloped fault.The northwest coal occurrence tectonic areas are large coal accumulating basins in early Middle Jurassic,reformed by later tectonic movement,and the structure around the basins are complex and fracture development and the formation dip angles are large and the interior of the basins are a wide and gentle fold structure and the inclination angles become slow.Taking the role of structure as the core of research,it shows a specific sedimentary system formed by the structural evolution of coal bearing basins and later transformation of coal bearing strata and accumulation and occurrence of coal resources,and the characteristics of coal control in different coal forming periods in Inner Mongolia under paleo-environment are inferred.