Study on coal seam occurrence features and control mechanism inLinyou Area of Ordos Basin

Linyou Mining Area is one of important new found coal abundance areas in Ordos Basin. Yan’an Formation is the main coal-bearing strata. In order to identify the concentrating coal characteristics and its control mechanism with dramatical variation and uneven distribution of lower coal seam thickness in Linyou Area, the coal-seam occurrence characteristics and coal accumulation and its control mechanism of the coal seam had been studied by using the method of coal accumulation inversion and trend analysis and tectonic stress analysis ,based on drilling information. In addition, the original tectonic geometry of coal accumulation basement had been recovered. The results showed that both thin and thick coal seams were deposited following a trend of coal seam thickness gradually increased from east to west and then it forms three coal rich areas. The floor of the lower coal seam was inclined to the NW and controlled by Indo-China Movement and Yanshan Movement. The occurrence characteristics of coal measures and coal seam was determined by basement topography, sedimentary environment and contemporaneous structure. Deposition and distribution of coal measure strata was determined by structural shape of triassic super face. Deposition and distribution of coal seam was controlled by contemporaneous structure in the early Yanshan Movement. The Yanshan Movement had changed the attitude of coal-bearing strata to a certain extent, but had very weak effect on the destruction and transformation of coal seams.