Eocene dinoflagellate cysts from the Popiele beds at Koniusza (Skole Nappe, Flysch Carpathians, Poland): taxonomy, biostratigraphy, and palaeoenvironmental reconstruction of a marginal marine basin
Przemysław Gedl
Studia Geologica Polonica, 136: 5-197.  PDF - Full-text Article


Institute of Geological Sciences, Polish Academy of Sciences, Senacka 1, 31-002 Kraków, Poland
ndgedl@cyf-kr.edu.pl

Abstract
A total of 152 dinoflagellate cyst taxa from the Popiele beds exposed at Koniusza (Skole Nappe, Flysch Carpathians, Poland) are systematically described. The biostratigraphical interpretation of their assemblages suggests Eocene (Bartonian and Priabonian) age. The dark-coloured fossiliferous mudstone that forms bulk volume of the olistostromic Popiele beds is dated as Priabonian; and the pale-coloured marl, mainly forming clasts, is Bartonian and Priabonian. Palaeoenvironmental analysis of palynofacies and dinoflagellate cyst assemblages suggests that the deposits studied were laid down on a shelf (subsequently redeposited into deeper parts of the flysch basin). The pale-coloured Bartonian marl settled down in an environment of relatively calm, hemipelagic deposition with limi- ted terrestrial influx, possibly in an offshore shelf under relatively oligotrophic surface water conditions; their sedimentary setting was presumably influenced by waters from lagoonal environments, manifested by a high ratio of near-shore taxa. The non-calcareous pale-coloured Priabonian mudstone was deposited in an even more offshore setting; its dinoflagellate cyst assemblage shows some similarities with the one from the offshore Hieroglyphic beds. The dark-coloured Priabonian mudstone settled down under a relatively high rate of a terrestrial material influx, presumably during period of a more intense freshwater input into the shelf basin, reflected by a high ratio of land-derived organic particles. This freshwater influx led to a minor eutrophication and a possible salinity decrease in the surface water layer. A comparison of dinoflagellate cyst assemblages from the Popiele beds with coeval ones from the neighbouring areas suggests that the Skole Basin was connected with epicontinental basin of south-eastern Poland during the Bartonian, whereas it was presumably isolated during the Priabonian.

Key words: dinoflagellate cysts, Eocene, Popiele beds, Carpathians, palaeoenvironment, biostratigraphy