Tectonic control on gas occurrence and distribution in Hunan Province

Applying the theory of step-by-step control on gas occurrence, combining with gas geological data of coal mines in Hunan Province,the paper discussed the tectonic control law of the gas occurrence, analyzed the gas zoning and the characteristics of gas zones. The results show that the geological structure in Hunan Province is complicated, the north was collided and compressed by north China plate, the west was jostled by Tibetan-Yunnan plate, the south was effected by Indochina plate, the east was collided and compressed by Pacific-Philippines plate for long time, making coal seam structures in Hunan Province severely destroyed, structures of coalfields complex, tectonic coal developed and seam thickness changed a lot. Intense magmatic thermal metamorphism increased the metamorphic grade of coal, resulting in significant influence on gas occurrence. Coal mine gas occurrence distribution in Hunan Province is divided into two high gasoutburst zones, one high gas zone and fivelow gas zones.