Petrography of the Paradise (No. 12), Baker (No. 13), and Coiltown (No. 14) coals of the lower portion of the Sturgis Formation (Pennsylvanian) in western Kentucky

Coal rank (based on vitrinite reflectance) and maceral composition were determined for 50 channel and borehole samples of the Paradise (No. 12), Baker (No. 13), and Coiltown (No. 14) coals in the Western Kentucky Coal Field. The three coal beds are in the lower part of the Pennsylvanian Sturgis Formation (Desmoinesian). Coal rank trends for the three coals vary across structural provinces in a similar and predictable manner. Coals in the Moorman syncline in the southeast are predominantly of high volatile C bituminous rank but approach high volatile B bituminous rank within the Pennyrile and Central fault systems that border the Moorman syncline. Westward, across the Central faults, rank of coals is high volatile B bituminous in the Webster syncline but increases to high volatile A bituminous northward, within the Rough Creek fault system. Coal rank in the Henderson basin north of the Rough Creek faults decreases to high volatile C bituminous. The Paradise, Baker, and Coiltown coals have consistently high percentages of total vitrinite (vitrinite and pseudovitrinite) (88% for the Paradise coal; 87% for the Baker coal; 85% for the Coiltown coal) and concomitant uniform low percentages of inertinites (less than 10% for each coal) (dry, mineral-matter-free basis). Total reactives (total vitrinite and liptinites) constitute 91% of the Paradise and Baker coals, and 90% of the Coiltown coal. Comparison of the three coals with stratigraphically lower coals in the Pennsylvanian of western Kentucky indicates that rank trends and maceral composition continue to be predictable, not only across the Western Kentucky Coal Field, but also within a large portion of the Pennsylvanian stratigraphic section.