摘要
五大连池火山群位于松辽裂谷的北端，这里的火山活动同裂谷的形成与发展密切相关。五大连池火山区发育着典型的“Ｘ”型断裂，其次是经向张断裂和纬向压断裂，它们是同一应力场作用下的产物。本文提出了“Ｘ”型断裂的形成与发展过程，并认为五大连池区处于“Ｘ”型断裂发展的第二阶段，即处于剪切应力的最大值阶段，两组断裂呈正交。在该阶段于“Ｘ”型断裂的交汇处，形成了张裂柱，这样一来．由于张裂柱群的存在，五大连池便成为明显的低压区，为火山喷发提供了有利的构造条件。本文以大地构造学说新见解──两极挤压说（李鸿业），阐述了松辽裂谷的形成与发展及其与火山活动的关系，提出了岩浆源压力的增长是火山喷发的内在因素，上部“Ｘ”型断裂张裂柱的沟通是火山喷发的构造条件，地球两极挤压的持续作用是构造活动的根本力源，五大连池的“Ｘ”型断裂决定了五大连池火山成网格状等间距的分布格局。
Wudalianchi volcanic cluster is located in the north tip of Sonliao rift.Its volcanism has a close relation with generation and development of the rift.There exist the″X″type faults,longitudinal tensile faults and latitudinal pressure faults in Wudalianchi volcanic area,which is caused by the action of the unified tectonic stress field.The relationship between the formation of the″X″type faults and volcanic activity is stated in this paper.The activity of Wudalianchi volcanic clusted is in the second development stage of the″X″type faults,i.e.maximum shear stress stage,in which the two sets of the faults is crosscut.Tension fissure post is produced at the crosspoints of″X″type faults.Thus.because of existence of tension fissure post Wudalianchi area becomes a low pressure region and has provided an available tectonic condition for volcanic eruption.In the light of two polar compression theory,a new idea on geotectonic,this paper has described the relationship between generation and development of Sonliao rift and volcanic activity,and suggested that increament of magma source compression is an interion factor to lead to volcanic eruption.Linking up the tension fissure post of upper″x″type faults is a tectonic condition for volcanic eruption.Lasting action caused by two polars compression is an essential force source for tectonic activity.The″X″type faults have determined the volcanic distribution pattern with network and equal-spacing in Wudalianchi area.
出处
《东北地震研究》
1996年第1期25-30,共6页
Seismological Research of Northeast China
关键词
五大连池
火山群
构造环境
构造特点
喷发机理
Wudalianchi volcanic cluster
Tectonic environment
Eruption mechanism
