刘家堡活动断层土壤气氡、 汞地球化学特征

应用FD-3017RaA测氡仪和JM-4数字金膜测汞仪在兰州市进行了野外现场勘察, 结果表明: ① 刘家堡断层土壤气氡、 汞具有明显的异常显示。 与气氡相比, 土壤气汞具有更好的指示性, 与断层位置有很好的对应关系; ②土壤气氡、 汞的典型异常形态为低-较高-高-较高-低的峰值形态。 单点异常大多数为观测中的干扰因素造成; ③ 在断层带上方氡、 汞的峰值异常一般比背景值高出2倍以上, 且具有成组特征, 即在断层带上方超过背景值2倍以上的点2个以上。 根据断层带土壤气氡、 汞的变化特征, 确定了刘家堡活动断层在不同区段的具体位置。 探讨了利用土壤气氡、 汞浓度形态变化特征判断活断层性质及产状的可能性。

Geochemical feature of radon and mercury across Liujiapu active fault

Concentrations of radon and mercury in soil gas were measured with ED-3017 Radon Meter and Jm-4 Mercury Digital Meter respectively in the field in Lanzhou. The result shows: ① The anomaly behavior of radon and mercury in soil gas across the Liujiapu active fault is obvious. The mercury is better than radon in indicating the fault location. ② The typical anomaly pattern of radon and mercury concentration is the peak shape with low-higher-highest-higher-low values. ③ There are a group of high values i.e. more than two points cross the fault, whose concentration of radon and mercury is over two times higher than the background value. The locations along different segments of Liujiapu fault are determined according to the variation characteristics of radon and mercury concentrations. Meanwhile, the possibility for determining the characteristics and attitude of the fault based on the features pattern change of radon and mercury concentration is also discussed.