Soil Radon Detection in the Tianjin Section of Cangdong Fault

In the active fault detection, 13 profiles of soil radon were arranged on the Cangdong fault. After measuring soil radon in the 13 lines, the location of Cangdong fault entering Tianjin was found. The location of the soil radon anomaly from the profile CF5 to CF11 has been detected and fault strike was delineated. However, the strike of Cangdong fault is not known in the area between CF5 and CF4 and north of CF11for no soil radon survey line arranged. According to the results of CF02, CF03 and CF04, the anomalous strike is obviously inconsistent with Cangdong fault and there may be another fault. The result of CF02 is obviously higher than that of other profiles. Such result indicates that soil radon measurement is greatly influenced by site conditions and there may be some problems in judging the activity of faults by soil radon measurement results.