REVISED STRATIGRAPHIC CORRELATION OF PRINCESS COALS IN NORTHEASTERN KENTUCKY

The stratigraphic framework currently in use for the Princess Reserve District of northeastern Kentucky relies heavily on coal bed correlations published in 7.5 minute geologic quadrangles. Many of these areas were mapped with limited information prior to the coal boom of the late 1970s and major highway construction in the last 25 years. Detailed stratigraphic work conducted along I-64, KY 23, OH 52, and WV 52 (Martino and others 1985,Merrill, 1986; Martino, in review) combined with recently acquired borehole data have enabled a more accurate picture to be developed for the Princess 7-10 coals and related strata in the Catlettsburg, Ashland, Boltsfork, and Argillite quadrangles. A crucial element that helped to unravel the stratigraphy is the recognition and correlation of the Lower Brush Creek marine zone which was described by Merrill (1986). Early workers were unaware of this unit in the vicinity of the town of Princess. Another important marker is the lowest stratigraphic occurrence of red bed paleosols which in Ohio typically occurs about 25 ft above the Upper Freeport coal (Sturgeon and Hoare, 1968). Uncertainty regarding the presence of the Upper Freeport coal in northeastern Kentucky compelled many previous workers to place the base of the Conemaugh at base of the lowest red beds. The Upper Freeport Coal-Brush Creek coal interval is typically about 90 ft in Ohio. These considerations combined with detailed correlations through the above mentioned quadrangles indicate that what has been described as the Princess 9 (Huddle and others 1963; Dobrovolny and others, 1963) is actually the equivalent of the Brush Creek coal. Furthermore, the Princess 7 described from these areas and thought to be equivalent to the Middle Kittanning (Chesnut, 1992) is the same bed described as the Upper Freeport from adjacent areas of West Virginia and Ohio. The lateral persistence of coal beds is frequently limited, though underlying paleosols often permit recognition of a given horizon. Variations in paleotopography may have limited accommodation space and necessary high water table conditions. The thickness and number of coal beds between the Obryan and Lower Brush Creek Limestone decrease from quadrangles south of the study area northward into the study area. This may be due to decreasing accommodation space northward toward the hingeline of the basin.