Effects of late Paleozoic foreland deformation on underground coal mine ground instability, Illinois and Appalachian Basins

This paper relates slickenside occurrences in the Pennsylvanian-age Springfield coal seam to local structural geologic features that are associated with the late Pennsylvanian-Permian Alleghanian orogeny. Because the slickensides discussed are interpreted to have formed in response to regional tectonic stress, small-scale controls on coal mine ground instability can be related to large-scale, regional tectonic processes. Field investigations indicate that mine-wide geologic mapping of structural geologic features can be used to project zones of subtle, yet problematic, structural weakness in advance of face positions. By incorporating this style of structural geologic hazard mapping in mine planning and operation, miners can be prepared to install appropriate supplemental support, or reduce the effects of structural weaknesses with local modifications to mine design.