Foraminiferal and palynological records of the Late Badenian (Middle Miocene) transgression in Podolia (Shchyrets near Lviv, western Ukraine)

Danuta Peryt, Przemysław Gedl, Tadeusz Marek Peryt

Abstract


The Upper Badenian marly shales overlying gypsum and the Ratyn Limestone at Shchyrets, Ukraine, contain moderately to well-preserved benthic (calcareous only) and planktonic foraminifers, and palynofacies dominated by bisaccate pollen grains, presumably transported by wind. Both foraminiferal and dinoflagellate cyst assemblages indicate an open marine environment with normal-marine salinity and cool waters. The palaeodepth was ca. 50 m except for the uppermost part of the section studied, where a distinctive deepening is indicated by the dominance of Uvigerina in benthic foraminiferal assemblages and a high P/B ratio. The water was thermally stratified and the differences between the bottom water and the water column show an upwards-increasing trend. Bulimina and Globocassidulina are the most common and dominant component of benthic foraminiferal assemblages, except for the uppermost part where Uvigerina dominates the assemblage. The composition of benthic foraminifer assemblages and δ13C values of foraminifers indicate nutrient-rich waters and mesotrophic to eutrotrophic environments in surface waters, and low oxygenation at the sea floor in the Ukrainian Carpathian Foredeep Basin during the Late Badenian.

 


Keywords


Paratethys, Carpathian Foredeep, Upper Badenian, foraminifers, dinoflagellate cysts, palaeoenvironment

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