Tunnel Seismics for Mineral Exploration – Is it Worth The Effort?

Active-source in-mine seismic surveys were conducted at Maseve mine, located in the Bushveld Complex (South Africa). Important aspects of the survey involved the testing and evaluation of seismic technologies, namely a land streamer and planted vertical component geophones, energy sources such as a 6.3 kg sledgehammer, 23 kg weight drop, and drilling machine. When comparing the sensing technologies, the land streamer provided better results in terms of structural imaging than planted geophones. This is because the land streamer is less sensitive to mine noise than the planted geophones. Furthermore, land streamer provided a quick way to set a survey, thus allowing for speed mapping of the geological structures. In terms of seismic sources, a sledgehammer provided a more cost-effective approach to seismic surveys than a weight drop. Although drilling provided some promising results, however, clever approaches will need to be developed to process such data. If successful, doing seismic while drilling could potentially increase the speed of the survey and reduce the cost of mapping, as well as increase the accuracy of imaging structures ahead of the mine face.