Response of coal seam deformation to structural evolution in Faer mining area,western Guizhou Province

Based on the observation of geologic structure in field and coal mine,combined with the analysis of coal seam macro-and microscopic deformation and regional tectonic setting,discussed the structural evolution and its controls on deformation of coal seam in Faer mining area.The results show that the tectonic framework of Faer mining area is mainly characteristicic by 'structural belt alternate with block,rhombic combination pattern'.Although mine structure of Faer Coal Mine is relatively simple,the indications of multistage structural activities are significant.The intense tectonic compression of NWW direction in Middle Yanshanian Epoch caused formation of reverse faults and folds trending NE in most areas and development of NW directed structures beside the boundary faults.NNE tectonic compression and dextral shearing action intensifies and modifies the early structures in Late Yanshanian Epoch and NE trending normal faults are formed by NW-SE extension.Cataclastic structural coal,mortar structural coal,and wrinkle structural coal,with deformation characteristics mainly involve the development of multiple brittle joint sets,mortar textures,and ductile folds respectively,are formed by structural deformation on coal seam.Early cleats in coal seam are commonly reformed into vertical bedding joints by Middle Yanshanian Movement.The difference in the development of bedding slip joints and the reformation of early structure formed in Late Yanshanian Movement leads to the differentiation in deformation characteristics of tectonically deformed coal.