The main goal of this research project is the reconstruction of paleoenvironmental changes during the Pliocene and Pleistocene in the wider area of the Republic of Croatia. Also, our goal is to determine the boundary between the Pliocene and the Pleistocene and to establish the character of the transition from the stable climatic conditions of the Middle Pliocene to the changing, Pleistocene climate dominated by glacial periods. The time frame for the Plio-Pleistocene transition will be determined by the method of cosmogenic nuclides. The provenance of the sediments will be determined by granulometric, modal, geochemical, XRD analysis of clay minerals and SEM analysis. The results obtained from all analysis will be statistically processed, and we will try to define the spatial relationship of sedimentary bodies using LiDAR images. The field survey will cover 8 locations and 2 boreholes from the island of Pag to Virovitica. Covering several regions, we want to analyze as many different sediments of Pliocene and Pleistocene age as possible in order to be able to reconstruct the paleoenvironment of the mentioned area. By applying the latest analytical methods, it is planned to significantly improve scientific knowledge about paleoenvironmental changes in the territory of Croatia during the mentioned epochs. The results of this project will contribute to a more precise creation of the Geological map of Republic of Croatia (OGK RH 1:50,000), revision of existing maps and a more precise separation of lithostratigraphic units.