Molluscs and ostracods of the Pleistocene loess deposits in the Halych site (Western Ukraine) and their significance for palaeoenvironmental reconstructions

Middle and Late Pleistocene loess-palaeosol sequence (MIS 12-MIS 2) from the Halych site has been divided into four loess beds, which represent different glacial periods and contain four interglacial pedocomplexes, as well as numerous interstadial and interphase palaeosols. Long-term interdisciplinary research, which has been conducted in this site, enables the detailed description of deposit lithology and precise determination of stratigraphic position of individual layers. Rich and diverse malacofauna occurs in loess deposits representing cold stages - MIS 12, MIS 8 and MIS 4-2. Seven molluscan assemblages of diverse composition and structure have been distinguished. Additionally ostracod fauna from the deposits representing MIS 8 is described. Faunal investigations enable the reconstruction of environmental changes during deposition of the studied sequence. The obtained results indicate that the Halych site may be considered as very important not only for the reconstruction of the Pleistocene geological history in western Ukraine but also for the studies of environmental conditions during the Middle and Late Pleistocene in the whole of Central and Eastern Europe.