In December, Dr Miha Marinšek successfully defended his doctoral dissertation entitled Taxonomy, biostratigraphy and palaeoecology of ostracods from Sarmatian and Pannonian sediments of eastern Slovenia. His doctoral research was carried out under the supervision of Dr Luka Galet from the Department of Geology, Faculty of Natural Sciences and Engineering, University of Ljubljana and the Geological Survey of Slovenia.

The PhD thesis deals with palaeontological, biostratigraphical and palaeoecological studies of ostracod assemblages from the Badenian, Sarmatian and Pannonian periods. Six sedimentary profiles from the area of eastern Slovenia were included in the study. A total of 256 samples were obtained, from which 129 ostracod species belonging to 54 genera were taxonomically determined. Based on the analysis, two biozones were identified in the area of Bizeljsko and four in the area of Imenska Gorce. In Bizeljsko, the two Badenian biozones were identified as follows Acanthocythereis hystrix - Bythocypris lucida and the Upper Pannonian Bakunella dorsarcuata Biocon. The Upper Badenian Carinocythereis carinata - Phlyctenophora farkasi, Lower Sarmatian Cytheridea hungarica - Aurila mehesi, Upper Pannonian Hemicytheria prisca subsurface Bakunella dorsarcuata bioconi. Palaeoecological interpretations suggest a deltaic sedimentary environment with fluctuating salinities between marine and freshwater conditions. Geochemical analyses of stable isotopes of oxygen and carbon and trace elements (Mg, Ca, Sr) in ostracod shells complement the palaeoecological findings. The interpretation of temperature data is limited by the small number of samples and the recrystallisation of the shells, while the trace element results partially support the palaeoecological interpretations. These results make an important contribution to the understanding of palaeogeographic and palaeoenvironmental changes in eastern Slovenia during the Upper Miocene.

The doctoral dissertation is available at here.