Date of Award
Master of Science (MS)
Subsurface electrical information can be obtained by electrical and self-potential methods. These geophysical methods, compared to drilling, provide a much cheaper option for investigating the hydrogeological setting. In this project report, we carried out resistivity and self-potential survey along Blacktail Creek in the Thompson Park area near Butte, Montana to understand the hydrogeological setting.
Three geophysical methods have been used: 2D electrical resistivity, 3D electrical resistivity, and self-potential. The least-square inversion resistivity model results showed a general variation of resistivity with depth and delineated the extent of the ground water. The ERT results show three electrical layers, one of them is a water filled alluvial sand layer with a resistivity range of 100- 200 Ωm; the layer under the water layer is weathered granite with resistivity range of 200-800 Ωm; resistivity ranges from 800-1100 Ωm indicating granite bedrock. The survey result from the 3D resistivity profile showed relatively high resistivity in the middle of the survey area interpreted as alluvial sand. The layers above and under the middle layer have low resistant, indicating water flow and water reserves. The self-potential result indicates there is a probable downward flow ground water in the area adjacent to the stream. This downward flow was interpreted as the creek is charging ground water. Environmental managers can refer to this knowledge to have a better sense of locations with high potential to hold ground water so beaver mimicry sites can be better located to leverage water storage.
Wu, Guolong, "A Geophysical Survey near Blacktail Creek in the Thompson Park area near Butte, Montana" (2020). Graduate Theses & Non-Theses. 234.