Evolution of the Pliocene-Quaternary landscape in the southeastern Alpine foreland (Slovenia): establishing allostratigraphy by employing geomorphology, sedimentology, and geochronology

Landscape evolution during the Pliocene and Quaternary was strongly influenced by abrupt changes in paleoclimate and tectonic regime. These changes were especially pronounced in the highly dynamic area of the European Alps and its foreland where the deposition of Pliocene-Quaternary terrestrial deposits took place. In the southeastern Alpine foreland (Slovenia), Pliocene- Quaternary fluvial sediments were deposited in several intramontane basins. They are preserved in terrace systems where the oldest Pliocene-Early Pleistocene terraces are located at the highest elevations and the youngest Late Pleistocene terraces on the lowest elevations. The study of these sediments requires a holistic approach that considers morphology, composition, and age. However, previous research on the Pliocene-Quaternary successions in Slovenia lacks a unified data set for the entire succession, systematic numerical age dating, and quantitative surface analysis that prevent reconstruction of landscape evolution. The proposed postdoctoral basic research project aims to fill this gap in Slovenian Quaternary stratigraphy. The main objective is to formalize the Pliocene-Quaternary allostratigraphic units in the Slovenj Gradec, Nazarje, Celje, Velenje, and Drava-Ptuj intramontane basins employing geomorphological, sedimentological and age dating methods. In work package 1, I will apply quantitative morphometric analysis to study the tectonic influence on the formation of fluvial terraces. The calculation of different morphometric factors will allow an objective comparison between the target basins. In work package 2, I will conduct a sedimentological analysis of the Middle-Late Pleistocene geologic sections to define the sedimentary environment and depositional and post-depositional processes. In work package 3, I will conduct a lithological analysis of the clasts to determine the origin of the Middle to Late Pleistocene sediments. Together with previous research on Pliocene-Early Pleistocene sediments will lead to the definition of the main source areas and drainage evolution during the Pliocene-Quaternary. In work Package 4, I will employ numerical age dating using optically stimulated luminescence and terrestrial cosmogenic nuclide dating. The ages will be crucial for defining the timing of sediment deposition and calculating sedimentation and uplift rates. Finally, in work package 5, I will synthesize the obtained morphological, sedimentological, and age dating data to determine the allomembers, alloformations, and allogroups. The proposed project will underscore as the first quantitative chronology in most of the target basins. Sedimentation and uplift rates will together with results of morphometric analysis contribute to the knowledge on the field of active tectonics and thus seismic hazard. The results will fill the fundamental gap in the Slovenian Quaternary geology by formalizing the allostratigraphic units. It will enable correlation of the Pliocene- Quaternary succession not only in Slovenia, but also in the Alpine foreland areas. Overall, the results of this project will make an important contribution for the discussion of Slovenian Quaternary stratigraphy in an Alpine-wide context.