The features and formation mechanism of structures in Burte mine

Aiming at the problems of minor-meso scale structures developed in Burte mining shaft, which restrict integrated mechanized mining seriously, through detailed underground geological observation and surface geo-logical surveys, the genetic types of structures, palaeotectonic stress field and structural formation mechanism are discussed from the view of structure geometry and tectonic origin. Research results show that the subsidiary folds in the Burte mine were settled under NNE-SSW compression stress in Yanan Formation during late Jurassic, which occurred in shallow structural layer. The deformation intensity was weak to middle. Broken interlayer gliding faults, rumpled interlayer gliding faults, composite interlayer gliding fault, high angle downthrown faults, and associated drag-folds were established by about NE-SW stretching stress, which caused a large scale of extensional sliding movement in Yan’an Formation in the late period of early Cretaceous. The basic structural framework in the mining shaft was formed by two stages of superimposed deformation.