浙江省珊溪水库地区土壤Rn和H2地球化学特征

在浙江省珊溪水库地区布设5条断层土壤气Rn和H₂测线，并选取15个溶解水氡采样测点。测量结果显示，其中有3条土壤气测线上的Rn浓度均值超过70 Bq/L，土壤H₂测值最高达1 377 ppm，水样中溶解氡浓度最高值为68.3 Bq/L。通过珊溪水库地区历史地震活动和地质构造情况分析，发现该地区土壤Rn、H₂和溶解水氡的高值分布区均与双溪—焦溪垟断裂F_11-3分支的空间位置密切相关，该断裂分支是珊溪水库地区小震活动的发震断裂。另外通过研究发现，历史震群活动距今时间以及震群活动的频度和强度是影响珊溪水库地区土壤气Rn和H₂地球化学特征的重要因素。

Geochemical characteristics of soil gases Rn and H2in Shanxi reservoir area, Zhejiang Province

In Shanxi reservoir area of Zhejiang Province,this paper set up 5 survey lines for fault soil gases Rn and H₂,then selected 15 sampling points for dissolved water radon.The results showed that the mean value of Rn concentrations in 3 soil gas lines is over 70 Bq/L,the maximum value of soil H₂ is 1 377 ppm,and the maximum value of dissolved radon concentration in water samples is 68.3 Bq/L.Based on the analysis of historical seismicity and geological structure of the study area,it is found that the high value distribution areas of soil Rn,H₂,and dissolved water radon are closely related to the spatial location of F_11-3 branch of the Shuangxi-Jiaoxiyang fault,which is the seismogenic fault of small earthquakes in the study area.In addition,we also found that the occurrence time,the frequency,and the intensity of historical earthquake swarm are important factors affecting the geochemical characteristics of soil gases Rn and H₂ in Shanxi reservoir area.