深部构造对吉林省东部火山与深震活动影响

Influence of the Deep Geological Tectonics on the Volcano and Deep Earthquakes in the East Area of Jilin Province

通过岩石化学分析手段及地球物理数值模拟方法,分析深部构造对长白山火山岩浆起源和深源地震发震机制的影响,认为长白山火山岩浆起源于地幔源区,并与太平洋板块深部俯冲有关;西太平洋板块深部脱水,产生陆内火山岩浆;俯冲板块的深部脱水产生的裂隙(断裂)可能是长白山区深源地震发震原因,且深源地震与火山作用有一定关联性。

The east area of Jilin Province has a special tectonic position,in which there are Changbai Mountain volcano and deep-focus earthquakes. The Changbai Mountain volcanoes with a high potential eruption possibility,are one of the most dangerous volcano in China,and the deep earthquake region is one and only in China. So,we investigate the influence of deep geological tectonics on the volcano and deep earthquakes,which has important scientific and practical significances of disaster prevention and reduction. The rock lithological analysis and geodynamics numerical simulation were combined to discuss the origin and formation mechanism of volcano and deep earthquakes. The results show that the magma source is mostly close to primitive mantle and the volcanism is related to the slab deep subduction.The Pacific slab deep dehydration is proposed to be the dynamic source of the intra-plate volcanoes. Dehydration faulting formed during the subduction are considered as the feasible formation mechanisms of the deep earthquakes. Besides,we infer that there is a correlation between volcanism and deep earthquakes in the region.