兰州市活动断层土壤气汞、氡地球化学特征场地试验

Field Test on the Geochemical Features of Radon and Mercury from Soil Gas on the Active Faults in Lanzhou

在兰州市主要活动断层上选择有断层露头或有钻孔资料的典型场地开展了断裂带土壤气异常特征及其影响因素的试验研究。结果显示断层带上方土壤气氡、汞不仅具有明显的峰值异常显示,而且其异常的形态特征对断层产状和断层性质有显著的反映,断层土壤气测量是活断层探测和研究的有效方法。结果还显示覆盖层厚度对断层带土壤氡、汞浓度的峰值形态及特征具有显著的影响。

Concentrations of radon and mercury in soil gas which were obtained on the main active faults in Lanzhou city are measured. The sample points were selected at the site where the outcrop of fault exists or there are borehole data. The result shows that not only the peak-value anomalies of radon and mercury in soil gas on the active fault show obviously, but also their shape characters reflect the fault location, fault property, and fault attitude well. It is proved that gas survey is a useful method for active fault ex- ploring and study. The result shows also that the shape and characteristics of peak-value anomaly of radon and mercury concentrations in soil gas on fault zone are affected by the overburden thickness.