In order to investigate sequences of toxic mine tailings that have settled in the bed of the Coeur d'Alene River, Idaho, (see figure 1) we improvised ways to make geophysical measurements on the river floor. To make ground penetrating radar (GPR) profiles, we mounted borehole antennas on a skid that was towed along the river bottom. To make induced polarization (IP) profiles, we devised a bottom streamer from a garden hose, lead strips, PVC standoffs, and insulated wire. Each approach worked and provided uniquely different information about the buried toxic sediments. GPR showed shallow stratigraphy, but did not directly detect the presence of contaminating metals. IP showed a zone of high chargeability that is probably due to pockets of relatively higher metal content. Neither method was able to define the base of the fluvial tailings section, at least in part because the IP streamer was deliberately designed to sample only the top three meters of sediments to maximize horizontal resolution.
Additional publication details
Tests of ground-penetrating radar and induced polarization for mapping fluvial mine tailings on the floor of the Couer d'Alene River, Idaho
Society of Engineering & Mineral Exploration Geophysicists
Mineral Resources Program
Larger Work Title:
Proceedings of the Symposium on the Application of geophysics to engineering and environmental problems: SAGEEP '97
Symposium on the Application of geophysics to engineering and environmental problems: SAGEEP '97