Volcanic Edifice Types of Xujiaweizi Fault and Their Geological Implications

Qingshen gas field exploration and development shows that isolated volcanic edifice control volcanic gas reservoir.Horizontal distribution of volcanic bodies and their projections become difficulties of volcanic exploration and development.Fine comparative study of volcanic formation of Yingcheng group of XJWZ fault is carried out,find that volcanic eruption control by the deep fault and have the feature of horizontal migration and vertical polycyclic superimposed.Volcanic edifice into the layer-shaped volcano,flat-shaped volcano,skew volcano,lava dome,caldera volcano five categories based on the geophysical response characteristics and their implications.Layer-shaped volcano and skew volcano shows that large-scale volcanic eruption along the tectonic fault zone and the eruption and extensive development of large areas of volcanic lava and pyroclastic rocks interbedded strata,these formation constitute main volcanic body of Yingcheng group.Volcanic edifice misfolding contiguous and volcanic reservoir developed.Flat-shaped volcano shows the strong weathering and erosion,weathering crust reservoir development and can form high volcanic gas reservoirs.Caldera and lava dome indicate the locality of volcanic activity.Caldera volcano is fast instant release of energy and formed large pyroclastic deposits,and mainly developed in tight reservoir.Volcanic lava dome is a product of late,relatively good reservoir,but small.