SEDIMENTATION AND PEAT ACCUMULATION ASSOCIATED WITH 
THE FIRE CLAY COAL IN EASTERN KENTUCKY 
COBB, James C., CHESNUT, D. R., and HANEY, D. C., Kentucky
Geological Survey, University of Kentucky, Lexington, KY 40506

The Fire Clay (Hazard No.4) coal in the Eastern Kentucky Coal Field is
part of a terrigenous clasticwedge that occurs between two transgressive
marine units, the Kendrick Shale Member and the Magoffin Member of the
Breathitt Formation (Middle Pennsylvanian). This coal contains an
estimated 6 billion tons of original resources and is one of the largest
producers of compliance-quality coal in the eastern United States.
Several environments of peat accumulation are inferred from coal-isopach 
geometry, trends in sulfur and ash content, and sedimentary features of enclosing 
strata.
	The Fire Clay coal generally thins to the west and northwest across
the Eastern Kentucky Coal Field. In the northern part of the coal field
this coal occurs in irregular and discontinuous patches which are
related to structural features. The thickest and most continuous
deposits are on the eastern flank of the Eastern Kentucky Syncline; the
coal becomes thin and discontinuous on the western flank of this structure. The 
thickest coal (>42 in.) occurs in lobes oriented perpendicular to the axis 
of the syncline. These lobes are low in sulfur and ash, indicating that peat 
accumulation was protected from marine and detrital influences. Coal of 
intermediate thickness (28-42 in.) is highly variable in sulfur and ash content. 
Linear trends of high ash content are perpendicular to the axis of the Eastern 
Kentucky Syncline and cut across areas of intermediate coal thickness, reflecting 
an influx of detritus. The thinnest coal (<28 in.), which is generally
higher in sulfur and ash, is associated with dark, fossiliferous shales,
demonstrating the proximity to marine conditions.
	Tectonism controlled the quantity and quality of the accumulating
peat by controlling fresh-water drainage, sedimentation, and marine
conditions.