Seismic Mapping Of An Abandoned Lead-Zinc Mine, Joplin, Missouri

In the mining of lead and zinc in the Joplin Missouri area, the open-pit method of mining was used if the ore extended<br>close to the surface or following the collapse of the underground operations. A regional hospital in Joplin Missouri<br>owns property in this mining region that in places overlies an infilled and abandoned open-pit lead-zinc mine. Much<br>of the infilled pit area has been covered by asphalt and is currently used as an open parking lot (about 62,500 ff). The<br>southern edge of the parking lot abuts a wing of the hospital complex; the eastern edge abuts a multi-storied parking<br>facility.<br>The hospital administration is considering erecting a multi-storied annex to the hospital wing on the asphalt parking lot<br>site. Recent subsidence of the asphalt paving occurred in parts of the parking lot which did not correlate with existing<br>maps that outlined the old open-pit mine location. To obtain a more detailed structural control at bedrock level, drilling<br>to bedrock and the acquisition of 25 parallel high-resolution reflection seismic profiles were undertaken. On the seismic<br>data, the bedrock reflector can be interpreted and spatially mapped across the parking lot from one line to the next. The<br>interpretation of the reflection seismic data was constrained and validated by the test boreholes within the parking lot<br>area.<br>This case study is presented as an example of the utility of the seismic technique for mapping bedrock in a structurally<br>complex area, and in a noisy urban environment with adverse surface conditions.