The Fire Clay (Hazard No. 4) coal is one of the leading producers in the Eastern Kentucky Coal Field, with more than 20 million short tons of annual production and 230 million short tons mined between 1976 and 1992, according to Kentucky Department of Mines and Minerals data. Regional thickness and resources of the coal are calculated in Greb and others (1999c) and Thacker and others (2000a, b).
Stratigraphically, the coal occurs in the middle part of the Hyden Formation of the Breathitt Group (Fig. 1), which was previously part of the Breathitt Formation (Chesnut, 1992). The coal occurs between the Upper Whitesburg and Fire Clay rider coals. Locally, each of these coals may almost merge with the Fire Clay coal, forming a zone.
Map and Chart 34
Digital Object Identifier (DOI)
Data collection was partly funded by the National Coal Resources Data System and National Coal Assessment Programs of the U.S. Geological Survey.
Greb, Stephen F., "Mining Geology of the Fire Clay Coal" (2003). Kentucky Geological Survey Map and Chart. 30.