Determination of contributors to coal seam structure in Sullivan County, Indiana

The structure of coal seams in Sullivan County, Indiana is subject to local variability controlled by differential compaction. Underlying Silurian reefs contribute to the maximum vertical variation and the underlying Mississippian unconformity surface controls the distribution of the most extensive and mappable structural features. The vertical magnitude, orientation, and lateral extent of the features should be considered during mine layout. Potential underlying Silurian reefs can be distinguished from other contributors to coal seam structure for the purposes of petroleum exploration.