VOLCANIC MASSIF GENETIC MECHANISM AND VOLCANIC FACIES CONTROLLED BY DEEP ZONE FAULTED SYSTEMS IN SONGLIAO BASIN: A CASE IN XUSHEN AREA
松辽盆地深层断裂体系对火山岩成因和火山岩相带的控制：以徐深地区为例

The deep zone of the Songliao basin includes three first-order structural units: palaeo-central uplift belt,eastern fault depression and western fault depression.Every unit is further divided into fault step belt,depression land,ramp region,and uplift zone between depression zones.Every structural zone consists of many faulted anticlines and block faults controlled by faulting.The deep zone fault system is composed of basement rifts,growth faults and small fractures.The whole structural unit presents both volcanic activities and tectonic movements.Faulting and volcanic actions together dominate the structural frame and formation development of the deep zone,as well as the types and distribution of volcanic facies.Volcanic activities caused by or associated with faulting lead to the basin filling of volcanic materials,reconstruct or mold the types of secondary units and structural frame of the basin,and make different tectonic positions develop differently.Volcanics are characterized by high-level eruption and low-level filling,having larger thickess along the crater.The deep zone fault system dominates the distribution of the volcanic massif and volcanic facies.