Mississippian (Serpukhovian; Chesterian Stage) coals from the Fluorspar District, Crittenden and Caldwell counties, Kentucky: Petrological and palynological compositions and their indications for peat-producing ecosystems

Serpukhovian Stage (Chesterian Stage in North American nomenclature) coals in western Kentucky are among the few occurrences of Mississippian coals in eastern North America. Thus, they provide a rare view of early Carboniferous peat-producing ecosystems. Petrographically, the coals are dominated by telovitrinites. Among the inertinite macerals, coprolitic macrinite provides evidence of arthropods fungal-degraded wood. Cutinite has an association with epiphyllous fungus. Owing to the relatively high spore contributions from arborescent Lycopsids, the coals bear a palynologic resemblance to the Pennsylvanian Langsettian through Asturian (Westphalian) coals preserved in the nearby Western Kentucky coalfield. The maceral assemblages, however, show a greater similarity to the Upper Pennsylvanian (Stephanian) coals in western Kentucky. With 66–67% total vitrinite and about 29% total inertinite (dominated by fusinite + semifusinite) (both as volume percent, mineral-fee basis), the Mississippian coals have significantly lower vitrinite percentages than the Westphalian coals. The petrographic similarity is not paralleled by a floristic similarity as the Stephanian flora was marked by the absence of arborescent Lycopsids. Overall, the amount of inertinites and the degradation suggested by a number of the inertinite forms suggests that, not unexpectedly decay and degradation was an important contributor to the Mississippian coals. As with any coals, the Mississippian coals represent a story of preservation more than that of degradation and destruction, with degraded and poorly-preserved fusinite and semifusinite, coprolitic macrinite, and remnants of fungi being the ghosts of the destruction of the biomass.