Paleogeographic meaning of psychrospheric Miocene ostracodes from the Fore-Carpathian Depression

Abstract

In the early Middle Miocene (Early Badenian) of the Fore-Carpathian Depression in Poland, a psychrospheric ostracode assemblage has been identified. Pre-Miocene and Miocene distribution of particular species of the assemblage, and particularly H. asperrima (associated with warm-water foraminifera) suggests that in the early Middle Miocene a deep and stratified basin extended from the Mediterranean to the northernmost part of the Central Paratethys, that was influenced by waters from the Atlantic Ocean, via the Iberian Portal. This probably allowed the psychrospheric Cluthia miocenica and Pseudocythere cf. caudata to invade later, in the Late Badenian, the northern part of the Central Paratethys, i.e. the Roztocze region, southern part of the Lublin Upland, southeastern Poland. Climatic deterioration and/or change of circulation, proposed by various authors for the Middle Miocene, enabled these species to survive in shallow waters of the Late Badenian of Poland.