Lithologic and geochemical investigations of the Fire Clay coal bed, southeastern Kentucky, in the vicinity of sandstone washouts

The Fire Clay (Hazard No. 4) coal bed of the Middle Pennsylvanian Breathitt Formation in eastern Kentucky is interrupted by a series of discontinuous sandstone bodies. This sand belt, which includes two washouts, was studied in Perry County. The coal thickens toward the interruptions and the coal between the sand bodies is highly disturbed. Several prominent durains in the upper bench of the coal bed are laterally continuous within the study area. Statistical analysis indicates that the durain layers contribute much of the vertical coal quality variation. The sandstone bodies are inferred to be a result of post-depositional fluvial activity and the disturbance of the coal between washouts is due to compaction-related slumping. A thin kaolinite-rich lens similar to the flint clay parting was found below the main parting.