Study On The Characteristics Of Coal-bearing Rock Series And Coal Accumulation Law In Hulusitai Mining Area,Inner Mongolia

The coal-bearing strata in Hulusitai mining area of Daqingshan coalfield are the lower part of the lower member of the Middle-Lower Jurassic Wudanggou Formation(J_1-2w).There are three group of coal seams seven-layer coals of J,K and L,and the main minable seam is J1 and J2 coal seams.The coal-bearing strata in the study area are generally of a monoclinic structure inclined to the south.The quality of coal is very low sulfur,low phosphorus,medium and high calorific value coal,and the coal is lean coal?SM14?.In this paper,Based on the structural analysis of the coal-accumulating basin and the theories of petrosedimentology,coal geology,coal chemistry,geophysics and sequence stratigraphy,the sedimentary environment and coal-accumulating model of Hulustai mining area in Daqingshan coalfield are discussed in this paper.The sedimentary center of the second member of the Wudanggou Formation of the Jurassic in Daqingshan coalfield is located in Shishi.The sedimentary environment of the Guaifaulted basin belongs to the continental Intermountain basin.The main structural traces of Daqingshan area are distributed in the East-West direction.The northern part is an ancient in situ uplift area,which is composed of Archean metamorphic rocks.The middle part is a Mesozoic Shiguai fault basin,and the southern part is a Daqingshan thrust nappe system.The sedimentary environment of coal-bearing strata in Hulustai research area is characterized by the cycle of fluvial and lacustrine facies.Coal seam mainly develops in the abandoned channel filling combination of braided river.The reason that J1 coal seam has a large distribution range and a large thickness of coal seam relative to other coal seams is that its development environment is a process from river facies to Lake facies.According to the analysis of coal accumulation regularity of Wudanggou Formation coal seam and the discussion of coal control factors in the study area,it can be seen that the coal control factors in the study area are mainly paleoclimate and paleostructure,in which paleostructure plays a dominant role,and multi-stage andcomplex tectonics provide sedimentary space for the peat swamp in the study area to control the boundary of peat swamp deposits,at the same time,the structure leads to the coal seam to the study area.The central part gathers.Coal seam metamorphism is mainly due to regional metamorphism.According to this study,it is inferred that area A in the west of the study area is a favorable area for coal prospecting,and area B in the east of the study area is a disadvantageous area for coal prospecting.