Dinoflagellate cysts and palynofacies from the upper Badenian (Middle Miocene) of the Roztocze area at Józefów and Żelebsko (Carpathian Foredeep Basin, Poland): palaeoenvironmental implications

Abstract

The post-evaporitic upper Badenian (Middle Miocene) succession of the Roztocze (marginal zone of the Carpathian Foredeep Basin) consists of shallow-marine sands and organodetrital deposits. The latter, although predominantly coarse-grained, include very rare and usually very thin intercalations of fine-grained, loamy material. A few such clay layers were sampled for their palynological content in quarries at Józefów (Józefów and Pardysówka) and Żelebsko. The clay samples yielded palynological organic matter, in contrast to organodetrital limestone samples, which were barren. The palynofacies composition, both presence/absence of land-derived material and the specific composition of aquatic material, are useful for the palaeoenvironmental reconstructions of sedimentary settings. During late Badenian time, the sedimentary setting of the deposits studied was characteri- zed by proximity to the shoreline, which, however, supplied limited input of terrestrial matter, and by restricted marine conditions caused by increased salinity. During the latest Badenian, water salinity presumably underwent a further increase, leading to the collapse of the dinoflagellate floras. The frequent occurrence of reworked Palaeogene dinoflagellate cysts in upper Badenian samples and their absence from the uppermost Badenian indicate variable intensity of erosion of the epicontinental Palaeogene strata during the Middle Miocene at Roztocze.