Features and Evolution Analysis of Coal-Controlling Structures in Zhangji Coalfield

The results presented that the faults in this area composed by three groups which head for EW, NE and NW etc. The patterns of the half-graben assemblage were divided into two styles which the former patterns are half-grabens formed by trailing faults, step faults and en echelon faults generated by a series of synthetic faults; and the later patterns are some kinds of grabens and horsts generated by a series of antithetic faults. Furthermore, the tectonic model of Zhangji mine field presents lineament structure, which composed by longitudinal belts with which separated by cross-range normal faults. The activities of these three sets of faults had transformed the initial transformed coal again, and formed a complex combination of half graben style structure which made the coal structure more complicated.