Dinoflagellate cyst, palynofacies and foraminiferal records of environmental changes related to the Late Badenian (Middle Miocene) transgression at Kudryntsi (western Ukraine)

Abstract

Qualitative and quantitative characteristics of the palynological content of the Upper Badenian strata at Kudryntsi (western Ukraine) indicate that this succession was deposited in variable environments. The basal siliciclastic series shows a very low content of palynological organic matter and palynofacies, which indicate a restricted environment and/or unfavourable conditions for the palynomorph preservation. The presence of dinoflagellate cysts (and composition of their assemblages) in the upper part of organodetrital limestones and the overlying rhodoid limestones indicates a typical shelf environment. Taxonomically variable dinoflagellate cyst assemblages from particular samples reflect gradual environmental changes – from environments of slightly increased salinity of seawater (strata overlying the siliciclastic series) to open marine, more remote environments during deposition of the upper part of the section examined. The gradual deepening of the sea and decrease of salinity is supported also by the succession of foraminiferal assemblages, which undergo gradual changes from Elphidium spp. assemblages, through Miliolidae assemblage, Lobatula lobatula assemblage, Neoconorbina spp. assemblage to Cibicidoides assemblage. The Late Badenian foraminiferal assemblage from Kudryntsi contains two species common for the Sarmatian, i.e. Elphidium reginum and Elphidium koberi, the latter species known so far from the Sarmatian.