Genesis of microstructure in coalfield in Meicheng-Hanpo'ao area of Hunan

The microstructural phenomena in the rock of Meicheng-Hanpo'ao area were analyzed from the microscopic scale, in combination with the regional tectonic background, the genesis of structure in the coalfield was analyzed from macroscopic and microscopic analysis. The results show that the study area is dominated by low temperature brittle deformation, multiple fracture sets show that the staggered development of the stress field in several times, the maximum principal compressive stress field of NW-SE direction in the first phase of Indosinian period was obtained by inversion of stylolites and the NE-SW compressive stress field in the second phase. The average differential stress is 50~70 MPa, shows that since the Indosinian tectonic deformation in the process of coal and rock experiencing tectonic stress action in middle low strength. Comprehensive conclusion is that the coalfield structure in the Meicheng-Hanpo'ao area was formed under the condition of multi medium and low intensity and complex tectonic movement dominated by brittle-ductile deformation.