Nappe structure characteristics and coal-controlling action of Tangshan mine in Kailuan

The thrust tectonic formed in the Mesozoic era has a terrific impact on the changes of coal seams, no exception for Tangshan mine located on the northwest to Kaiping coalfield on Tangshan block depression. Based on the regional background and structure rules of Tangshan mine, and combined with the theories of geometrical characteristics, kinematics and dynamics, this paper discussed the characteristics of thrust tectonic by taking F_III reverse fault as the dominant factor. The result shows that the trend of nappe structure is approximately parallel with axis of folds in the coal field, trending NE along the formation strike. The nappe structure was inversely moved from NW to SE. The intensive compression between the Kula-Pacific plate and the Eurasian plate of early-middle period of Yanshan movement was the main power to form this nappe structure. Besides, controlled by folds and faults, especially by nappe structure, the variation of coal seam thickness is remarkable, and coal bunkers appear partially, which is inconvenient for mining coal.