Vegetational patterns in the Herrin and Springfield Coals (middle Pennsylvanian of Illinois), based on miospore profiles with comparison to coal-ball patterns

Palynological profiles based on small incremental coal samples of the complete seam established the intraseam variation at two coal-ball localities in the Herrin and four localities in the Springfield Coal. These were the first intraseam profiles collected adjacent to coal-ball profiles and show a broad correlation between changes in miospores and changes in source vegetation in the petrified peat (coal-balls) deposits, especially in the Herrin.; The miospore profiles show changes distinctive enough to subdivide the Herrin seam into vegetational phases (more distinctive at the Sahara locality). Major vegetation changes occurred at the clastic “blue band,” which marks an over-the-bank splay deposit, especially with some tree-fern (Punctatosporites minutus and Laevigatosporites globosus ) and sphenopsid (Laevigatosporites large spp.) spores. Miospore changes were also correlated with changes in coal lithotypes and changes in preservation categories of miospores.; Local variation at one locality in the Herrin is documented by comparing amounts of individual miospores in two profiles separated by 381 meters. Many miospore taxa show very similar changes in abundance at the same level of the seam. Patterns of Lycospora are very similar at the two sites (R2 = 0.79669 with linear regression). Patterns of combined tree-fern (Psaronius) are also similar, but with different miospores abundant in each profile. The top coal zone (high in Diaphorodendron , and Endosporites globiformis) is distinctive showing the most variation between profiles.; Miospore distribution patterns suggest differences in some ecological requirements of their source plants. One of the major tree-fern miospores, Thymospora, shows a pattern different than some of the other tree-fern miospores, especially at Sahara where it rises to second in abundance in the top zone at 29%. Thymospora is less abundant (less than 16%) in the two most complete profiles from Old Ben, but at both localities shows less rapid changes in abundance than two other Psaronius miospores. Perhaps the tree fern that produced Thymospora occupied less disturbed sites.