ABSTRACT
The Shanghaimiao Coal Mine is located in the southwest of the Inner Mongolian Autonomous Region, on the northwestern edge of the Erdos basin, which is under the jurisdiction of the Shanghaimiao Town, Etuoke Front Banner, and located in the border zone between the Inner Mongolian and the Ningxia Hui Autonomous Regions. The Shanghaimiao Coal Mine is like a trapezoid, with the northern boundary of the banner boundary of Etuoke Front Banner, the southern and western boundaries of provincial boundaries between the Inner Mongolian and the Ningxia Hui Autonomous Regions, and the eastern boundary of Jurassic coal reservoir at the 1200 m deep. The whole area of this mine is about 1154 km2, with the south-to-north length of 67 km and the east-to-west length of 34 km. The area with coal deposition is about 850 km2. According to the general plan of the Shanghaimiao Coal Mine, the coal resources/reserves of this mining area is about 14262.65 Mt, which includes the proved intrinsic economic resource of 1619.38 Mt, the controlled intrinsic economic resource of 2929.62 Mt, the inferred intrinsic economic resource of 6378.21 Mt, and the
2 OVERVIEW OF GEOLOGICAL BACKGROUNDS OF INVESTIGATED AREA
The Shanghaimiao Mine is closely adjacent to the western wing of Tianhuan Depression of the Erdos Basin, belonging to the North China Plate. The overall formations incline eastward, and the coal mine is located on the eastern wing of the Shanghaimiao Anticline with the axis orientation of N12°W, and the axial plane inclines eastward at the dip angle of 85°. The two wings of the Shanghaimiao Anticline lay out symmetrically with the formation dip angle of 6∼15°. There is no magmatite revealed by the geological investigation in the coal mine area. For the geological formations in this mine area, the formation belongs to the western edge of Dongsheng-Huanxian sub-zone of Erdos zone, which is adjacent to the eastern edge of Majiatan-Pingliang subzone, one of Erdos zone. The geological structures in the basement of the Erdos basin is very stable, and these structures controlled the evolution of Mesozoic basins, sedimentary infilling, and the growth of coal reservoirs. The major geological structures are indicated in Figure 1. The revealed formations in the mine area (by geological drilling investigation) include Quaternary formation (8.7 m thick), Tertiary formation (103.0 m thick), Cretaceous formation (283.0 m thick), Jurassic formation (198.0 m thick), Triassic formation
(1184.0 m thick), Permian formation of Qianfeng group (348.0 m thick), Permian formation of Shihezi group (333.0 m thick), Permian formation of Shanxi group (78.0 m thick), Carbonic formation of Taiyuan group (83.0 m thick), middle Ordovician formation (162.0 m thick), lower Ordovician formation (319.0 m thick). The major lithology disclosed by the geological drilling investigation (based on the statistical results of rock cores) includes coarse sandstone (accounting for 12.91%), medium-grained sandstone (accounting for 28.91%), post stone (fine-grained sandstone accounting for 21.92%), and the above-mentioned rudacesou rock accounts for about 63.74%. The siltstone accounts for 26.98%, the mudstone accounts for 3.53%, and the coal formation accounts for about 5.74%.
