Integrated geophysical approach using electrical resistivity tomography and multichannel analysis of surface wave in assessing Wilson Spring development

This research investigated fractured zones leading to preferential flow paths of Wilson Spring. In this context, electrical resistivity tomography (ERT) data and multi-channel analyses of surface waves (MASW) data were acquired at studied site with the purpose of mapping a variable depth to top of bedrock and geological structures. Interpretation of the boreholes, MASW, and ERT data indicated that a depth to top of rock does vary significantly at the studied site due to many solution-widened fractures. Multiple near-vertical solution-widened fractures were mapped in the studied site based on the interpretation of the ERT data. The mapped solution-widened fractures appear to be trending north-south, almost perpendicular to the ERT traverses (west-east), and however it is possible they extend at oblique angle to the ERT traverses. The conducted geophysical survey is the first attempt to map geological structures and karst features that might be possible access of underground water. The underground water expose on land surface through fractures to develop Wilson Spring. Thus the seepage pathway near or beneath Wilson Creek is interpreted as through a solution-widened fractures. ERT method has proven to be effective in mapping variable depth to bedrock and solution-widened fractures. The MASW method and boreholes data were able to map variable depth to top of bedrock --Abstract, page iii