汤东活动断裂带土壤H2、Rn地球化学特征

摘要

为研究汤东断裂带土壤气体地球化学特征及其所反映的构造地球化学背景,采用野外监测的方法分析了张河村与邢李庄村两条测线的土壤H2、Rn分布特征.结果表明,张河村H2浓度、Rn活度浓度的分布范围分别为0.24×10-6～174.7×10-6、13.3～69.8 kBq·m-3,背景值分别为14.26×10-6,24.8 kBq·m-3.邢李庄测线H2浓度、Rn活度浓度的分布范围11.8×10-6～67.06×10-6、43.6～72.6 kBq·m-3,背景值分别为37.13×10-6、72.6 kBq·m-3.张河村测线在90～105 m处,H2、Rn出现强烈高值异常,而120～150 m处出现高值异常.异常值位于断裂带附近,H2、Rn气体测值对断裂位置具有良好的指示作用.气体异常主要受汤东活动断裂构造控制,汤东断裂下方的深大断裂和汤阴地堑中下地壳的低速体对深部气体释放有重要作用.%In order to study the geochemical characteristics of soil gas and the tectono-geochemical background reflected by fault gas in the Tong-Dong fault zone, the field monitoring method was used to analyze the concentration distribution of soil H2 and Rn in the two observation lines of Zhanghe village and Xinglizhuang village. The results show that the distributions of H2 and Rn concentration in Zhanghe village ranged from 0.24 to 174.7×10-6 and 13.3 to 69.8 kBq·m-3, respectively. The background values of H2 and Rn concentration are 14.26×10-6 and 24.8 kBq·m-3, respectively. The range of concentration distribution of H2 and Rn in Xinglizhuang observation line ranged from 11.8 to 67.06×10-6 and 43.6 to 72.6 kBq·m-3 respectively, with background values of 37.13×10-6 and 72.6 kBq·m-3, respectively. In the measure line of Zhanghe village, strong anomaly of H2 and Rn appeared at 90～105 m, but a higher anomaly occurred at 120～150 m, with anomalous values near the fault zone, which indicates the location of the fracture effectively. Integrated geological structure and physical geography, it is concluded that the high value anomaly of the gas composition in the survey line are mainly controlled by the tectonic conditions, and it is also affected by sediment properties and meteorological factors. Therefore, we should further track and monitor the gas composition in the soil layer of the target fault zone, and analyze the temporal and spatial variation of fault activity, and take gas isotope techniques to explore the source of the components, so as to enhance the important role of gas geochemical indicators for fault tectonics activity and to strengthen the efficiency of earthquake prevention.