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ISSN 2096-7780 CN 10-1665/P

吉林省地壳厚度与vP/vS比值及其构造暗示

Crustal thickness and vP/vS ratio and their tectonic implication in Jilin Province

  • 摘要: 基于松原地区布设的5个流动地震台和搜集的吉林省密集地震台站下方的地壳厚度与vP/vS比值,分析了该区不同构造地质单元的地壳结构特征。结果表明:吉林省地壳厚度平均值为32.57 km,中间薄两边厚;vP/vS平均值为1.768,表现为东高西低。长白山区地壳厚度整体比松辽盆地高,呈东厚西薄;vP/vS比松辽盆地要低但整体变化不大,火山喷发区地壳厚度薄且vP/vS值高;松辽盆地地壳厚度东薄西厚,vP/vS比值东高西低,两者显示出负相关性,两个地震集中区域松原和前郭都表现出地壳厚度的强烈的横向变化和高的vP/vS比值;松原地区具有吉林省最薄的地壳厚度和最高的vP/vS

     

    Abstract: Using data on crustal thickness and the vP/vS ratio calculated from teleseismic waveforms recorded at five temporary stations and collected from previous studies in Jilin Province, we analyzed the crustal structure in different geological units. The results show that the average crustal thickness in Jilin Province is 32.57 km with thinner crust in the middle; the average vP/vS is 1.768 with higher values in the eastern region; crustal thickness in Changbai Mountain area is higher than that in the Songliao Basin, whereas the vP/vS ratio is lower than that in the Songliao Basin. The crustal thickness in the Changbai Mountain area is thin in the west, the vP/vS ratio shows small variation, and the thin crust with the high vP/vS ratio appear in the volcanic eruption area. In the Songliao Basin area, the crust is thin in the east with a high vP/vS ratio, whereas the Songyuan and Qianguo areas with dense earthquakes exhibit substantial lateral changes in crustal thickness and high vP/vS ratios. The thinnest crust and the highest vP/vS ratio is found in the Songyuan area in Jilin Province.

     

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