Abstract: The geochemical feature of mercy in soil-gas across the Sanhe-Pinggu active fault that was formed by strong earthquake (M8.0) in 1679 in Hebei Province, North China was discussed. Concentrations of mercury in soil gas were measured with QM201G Mercury Meter in the field. Mercury concentrations are in a wider range of 0.001~0.246 ng/L, with background value of 0.015ng/L. The zone of mercury anomalies occurs along the fracture zone and mercury density becomes as higher as 10 times compared with background value. The anomaly zones of mercury in soil gas indicate that there are two buried faults with strike of 45~60°NE, which is consistent with the reported results of geological and geophysical survey.

Key words: Soil gas, Mercury geochemistry, Active fault, Earthquake