辽宁金州断裂断层土壤气地球化学调查

Study on Geochemical Characteristics of Soil Gas cross Jinzhou Fault in Liaoning Province

摘要:

对辽宁南部地区重点活动断裂的8条剖面进行跨断层土壤气Rn、CO₂和H₂浓度测量。测量结果表明，各测量剖面土壤气Rn、CO₂和H₂的浓度平均值变化范围分别为10.65~39.50kBq/m³、0.59%~3.37%和9.74~306.28ppm。研究区土壤气Rn、CO₂和H₂浓度异常主要集中在海城老震区和盖州震群地区，土壤气空间变化特征显示Rn、CO₂和H₂浓度从南至北有逐渐增高变化趋势，这与辽南地区地震活动分布、地下低速层分布、地质特征及地壳垂直变形速率等变化相对应，表明辽南地区金州断裂土壤气地球化学特征主要受控于辽南地区地震活动、地下介质结构和地壳垂直形变速率的影响，同时也受到测量场地地质特征的影响。

Abstract:

The concentration of soil gas Rn, CO₂ and H₂ were measured cross Jinzhou Fault along totally 8 profiles in the southern area of Liaoning. The results showed that the average concentrations of soil gas Rn, CO₂ and H₂ varied from 10.65 to 39.50kBq/m³, 0.59% to 3.37% and 9.74 to 306.28 ppm, respectively. The distribution of anomaly concentrations of soil gas Rn, CO₂ and H₂ concentrated within the Haicheng, Gaizhou area and its nearby. There exists a clear spatial distribution feature in which the concentration values of soil gases in the northern area of Liaoning were higher than those in the southern region within the study area, which could be attributed to characteristics of the earthquake spatial distribution, low velocity distribution, geological of the observation site and vertical crustal deformation rate. These geochemical characteristics in the study area might be mainly controlled by the seismic activity, crustal structure and vertical crustal deformation, as well as the geological condition on site.