沧东断裂天津段的土壤氡探测

Soil Radon Detection in the Tianjin Section of Cangdong Fault

活断层探测中,在沧东断裂上布设13条土壤氡测线,经对13条测线的土壤氡测量,找到了沧东断裂进入天津的位置;探测到从CF5测线到CF11测线间沧东断裂的土壤氡异常位置,划出了它的走向;而在CF5与CF4之间以及CF11以北的区域,由于没有布设土壤氡测线,沧东断裂的走向没有探明。从CF02、CF03、CF04三条测线测量结果分析,其显示的异常走向与沧东断裂明显不一致,判断可能有另外一条断裂的存在;CF02测线测量结果明显高于其他测线,说明土壤氡测量受场地条件的影响较大,也说明利用土壤氡测量结果判定断裂的活动性可能存在问题。

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 CF11 for 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.