Thrust Systems In The Eastern Segment Of Daqingshan, Inner Mongolia

The eastern segment of Daqingshan is located in the middle part of Inner Mongolia, China and in the northern margin of North China platform. It belongs to the realm of the collision belt of Siberian Block and North China Block. The study area is in the south of Siziwangqi, Outcropped strata in this area are: Wulashan group of middle Archaeozoic, Seerteng group of late Archaeozoic, Majiadian group of Lower Proterozoic Subera, Shinagan formation of Sinian, Shuanmazhuang formation of Carboniferous, Dahongshan formation,Naobaogou formation and Laowopu formation of Permian, Wudanggou formation,Daqingshan formation of Jurassic and Lisangou formation of Cretaceous. Magmatite in this area are mainly Permian granodiorite Triassic granite and Jurassic moyite.According to the field study, it′s found that the structural framework of the study area is controlled by a series of nearly E-W striking imbricate thrust systems(As a representative, the Daqingshan overthrust system is moved from south to north and its trending length is about 120 km and the shortening is at least 11 km.), and there is also thrust which is moved from north to south(As a representative, the Panyangshan overthrust system′s trending length is about 70 km and the shortening is at least 7.1 km.). The nappes often be eroded to the main fault surface and to the strata of the footwall, therefore, a lot of klippen and windows are propagated in this area.The thrust system of Daqingshan area consists of a series of nearly EW striking imbricate thrust faults which is moved from south to north and in different scales,structural rock masses between thrust faults,various fault folds and so on.The thrust system maybe controlled by the deep tectonic movement and the structural stress field with a S-N extrusion. The collision between North China Block and Siberian Block is the main cause of the development of the thrust system. The timing of the thrust system's development should be at least two periods—Indo-Chinese epoch and early Yanshanian.The strata(Shuanmazhuang formation of Carboniferous and Wudanggou formation of Jurassic) under the thrust nappes contain coal in the area, there are outcropped windows where are strata contained coal, the quality of the coal is good and the coal bed is thick. Therefore, it will be the potential base of energy in the area in the future.