Late Glacial and Holocene sedimentary record at Pirovac Bay (Dalmatia, Croatia) reveals freshwater and marine ostracods

The distribution and composition of ostracods of the Late Glacial and Holocene in the two cores Prosika 1 (742 cm) and Arta 1 (150 cm) from the karst depression Pirovac Bay can be used to reconstruct palaeoenvironmental conditions and can be interpreted in the context of hydrological conditions and the evolution of the Pirovac Bay during the 14, 100 year-long records. Forty-seven ostracod species from non-marine and marine families Darwinulidae, Candonidae, Ilyocyprididae, Cyprididae, Cytherideidae, Limnocytheridae, Leptocytheridae, Loxoconchidae, Cytheruridae, Trachyleberididae, Cytheromatidae, Pontocyprididae, Hemicytheridae, Xestoleberididae are recognized. Considering results of the multiproxy investigation (palaeontological, lithological, geochemical, and geophysical data), especially ostracod assemblage composition and the presence of benthic foraminifera, two main zones, a freshwater zone (FZ) and a marine shallow-water zone (MZ) with one transitional subzone (TS) are detected. The FZ is characterized by freshwater species typical for the paleoenvironment of an organic-rich, low-energy wetland. In the MZ marine ostracods are represented by shallow marine species. In this zone, marine ostracods are mixed with various allochthonous freshwater taxa. Their mixing can be explained due to the specificity of the karst terrain and the existence of vruljas (freshwater springs under marine water). Between the two zones, the TS includes abundant lake freshwater taxa with rare marine ostracods and benthic foraminifera. The occurrence of rare marine taxa in the TS is connected to the global sea-level rise and first incursion of marine water in Pirovac Bay.