Facial variability of gypsums, speleogenesis, and morphology of karst cavities: new insights from Polyakova Ducha Cave (Chernivtsi region, Ukraine)

The research focuses on studying the facies diversity of the Miocene gypsum sequence within the Polyakova Ducha Cave, located at the junction of the Pre-Carpathian Foredeep and the East European Platform (Chernivtsi region, Ukraine). A detailed lithological and stratigraphic analysis of the gypsum facies on the polished walls of the cave galleries was conducted, allowing for the reconstruction of the depositional conditions. Five main gypsum facies were identified, each corresponding to different stages in the development of the Miocene evaporite basin. It was determined that the formation of the lower part of the gypsum sequence was accompanied by earthquakes. The cave’s morphology indicates its complex speleogenesis, involving both hypogenic and epigenetic karstification processes. Correlation was established between the stratigraphy of the gypsum facies and the mesomorphological features of the cave. This enabled the reconstruction of the evolution of the underground cavity and the identification of factors influencing karst development. Keywords: sulfate sequence, gypsum, karst, facies, Miocene, cave, morphology.