The Mechanism of Volcanic Rock Fracture Formation of Eastern Sag of Liaohe Depression

Structure fractures are the main types of secondary fracture. It can be divided regional fracture and local fracture. Local fractures conclude vertical anticline and across anticline and fault related fracture. The related stress field of regional or local fracture is consistent with regional or local stress field. The processes of different grades and different periods tectonic movement are the processes of regional and local fracture generation and superpose. The structure fractures generation of the area are consistent with changing of the stress field controlled by stronger effect episodes of Xishanian Movement Ⅱ,Ⅲ,Ⅳ. Structure fracture's scales are relatively big, the distributions are vast, the research degrees are high, and the principles are better and appearing regularly. The volcanic rock is usually low pervasion, there are a lot of the original fractures and pores, but most of them is not connected well, and became inefficacy space. The development of structure fractures are important for volcanic rock to become advantageous reservoir and connect the original fracture and pore. Above all, the meaning of the research of the mechanism of volcanic rock fracture formation is significant.