Structural Features And Tectonic Coal-controlling Effect Of Wugou Coalmine, Huaibei Coalfield

Based on systematic analysis of geological data concerning Wugou coalmine,combined with tectonic evolution, structural development features and regularities havebeen discussed. The stress-strain conditions have been revealed through the research ofcharacteristics of tectonic deformed coal and rocks and the vitrinite reflectance of coal.Combined with the superimposition and transformation of structures, the geneticmechanism has been deeply discussed by systematically studying the regional tectonicsettings and the control of medium condition. The controlling effect of different types ofcoal-controlling structures have been discussed. The following conclusions have beenmade:(1) Wugou mine area can be divided into3structural zones: complicated faultedzone in the north, superimposed folded zone in the middle and structurally complicatedzone in the south; faulted structure combination forms have λ type, anti-λ type, Y type,anti-Y type, graben-horst type and stepped type. The fractural structure is generallycomplex in Wugou coalmine and the complex areas are mainly distributed near to the largeand medium-sized faults and reverse faults.(2) The structures of Wugou coalmine were formed in shallow brittle deformationenvironment of low temperature and low pressure, the stress-strain environments formingtectonically deformed coal can be classified into three types, i.e. brittle cataclastic, ductile,and shearing. The formation of which is mainly related to the collision of South Chinaplate and North China plate, and the subduction of the Pacific plate to the east Chinacontinent. Wugou coalmine has experienced NS compression of the Indo-Chinese epoch,NW-SE compression of the early Yanshan epoch, tectonic stretching of middle and lateYanshan epoch and NS stretch of the Himalayan epoch. EW and NE structures wereformed and reformed during the above periods. The strongest NW-SE compression duringthe early Yanshan epoch was revealed by the strain analysis results of coal vitrinitereflectance ellipsoid.(3) The development of minor faults is obviously controlled by medium conditions.The minor faults are more likely develop in the area of hard rock distribution and of lowmudstone ratio of coal roof and floor.(4) The coal-controlling structural styles of Wugou coalmine can be divided intomonoclinal fault block, tilted fault block, graben-horst structure, fold-fault structure andsuperimposed fold structure. The deferent structural styles control the distribution of coal in deferent ways.