Abstract
The rock salt layers underlie at shallow depth under 50m-100m in depth and saline groundwater is distributed in Phra Yuen area, northeast Thailand. The G1 and F 1 faults were inferred by analyses of geological columns at 16 sites (A1-A16) of the regular 1 km grid covered 3km×3km area and photo-lineaments interpretation. The electromagnetic prospecting, the electric prospecting, and the soil temperature survey at 1m depth were carried out along the survey lines of A5-A7 and A10-Al2 to verify the inferred faults. The conductivity sections by electromagnetic survey showed the vertical distributions of high conductivity zone around the inferred G1 and F 1 faults. The resistivity section showed the vertical distributions of high resistivity zone around F1 fault. The results of soil temperature survey revealed an anomaly low soil temperature zone over the F 1 fault. The cross-check of different methods of physical prospecting ensures the possibility of inferred G1 and F 1 faults. The monitoring result of groundwater showed that the electric conductivity of groundwater changes seasonally and locally. The evidences of groundwater with a high electric conductivity and distribution of ponds with water salinization along inferred faults support that fault has a function of pathway for upward movement of the saline groundwater.
