长白山天池火山区浅部构造特征研究

2002年在长白山天池火山区完成了10条测线的浅层地震探测和6条测线的超浅层地震探测. 结果表明，在整个勘探区内存在3个稳定的浅层地层界面，个别区段的浅层地层界面多达7个，而在500 m深度以下没有出现明显的反射震相. 天池西南部的地层层位个数明显多于天池西北部，这表明天池西南部的断层对火山喷发熔岩流向较天池西北部的断层有更强的控制作用. 探测中发现6条浅部断层，这些断层大都近于直立，成地堑式，多分布在天池火山口的西南侧，这说明天池西南部的火山活动比天池西北部更为强烈, 从而推测天池火山的主控断裂即北东向的六道沟——天池——甑峰山断裂比北西向的白山镇——天池——金策断裂的活动性更强. 

STUDY ON SHALLOW STRUCTURAL FEATURES IN CHANGBAISHAN TIANCHI VOLCANIC REGION

A seismic survey by 10 shallow profiles and 6 ultra-shallow profiles was performed in Changbaishan Tianchi volcanic region in 2002. The result shows that there are three (in some areas as many as seven) stable interfaces in the survey region, but no reflection phases are found in depths greater than 500 m. The number of interfaces in the southwestern part is obviously greater than in the northwestern part of Tianchi volcano, which suggests that the faults in the southwest have a stronger controlling power over the flow direction of volcano-spewed lava as compared with those in the northwest. Six shallow faults exist in the survey region. The shallow faults are nearly vertical graben-like faults and are mostly distributed on the southwest of Tianchi crater, indicating that volcanic activities in the southwest are stronger than in the northwest. On this ground, it could be further deduced that the NE-trending major fault of Tianchi volcano-Liudaogou-Tianchi-Zengfengshan fault-is more active than the NW-trending Baishanzhen-Tianchi-Jince fault.