Paleoecology of migrating carboniferous peat environments
Abstract Evidence for a genetic relationship between the distribution of spore-and-pollen assemblages in the Lower Kittanning coal and the distribution of marine and non-marine facies in the overlying Lower Kittnning shale is presented. Previously published geochemical, lithological, and invertebrate faunal criteria separate the facies of the Lower Kittanning shale into marine (including restricted-marine) and non-marine origin which geographically coincide with the distribution of assemblages in the upper zones of the coal seam. Palynological zones in the Lower Kittannig shale, as well as the relationship between sulfur in the seam and the facies of the overburden, support the hypothesis of causative factors responsible for the spatial distribution of spore-and-pollen assemblages in the coal and overburden. Peat accumulation in the coal swamp peripheral to the basin was initiated by Lycospora -producing lycopods on a surface which may have previously been occupied by an Endosporites -producing lycopod and gymnospermous (e.g., Florinites, Guthoerlisporites, Wilsonites, Potonieisporites ) forest. As the coal swamp became more brackish with the incurring marine transgression, the lycosporid lycopods migrated towards the more fresh backswamp areas and were replaced by the lycopods which disseminated Densosporites microspores.