Quantifying Sediment Dynamics and Grain Size Characteristics in the Swiss Molasse and Quaternary Deposits

The Molasse basin recorded over the course of more than 30 Ma the evolution of the Central Alps, which underwent changes in tectonic processes and experienced shifts in the paleo climate. A common feature that records such changing conditions are variations in the sediment flux – the amount of supplied material – that was released from the catchment and stored in the foreland basin. Early attempts to estimate sediment fluxes date back to the 19th century, and subsequent approximations refined these estimates, leading to a more comprehensive understanding of sediment budgets throughout the Oligo- and Miocene times. However, these assessments were based on the entire basin's scale. This thesis shifts the focus to determine sediment fluxes at the scale of individual megafan systems that were recorded by numerous stratigraphic sections encountered in the Swiss Molasse Basin. It further delves into the topic to unravel the sedimentary dynamics of the paleorivers on these alluvial megafans and provides insights into the sedimentary dynamics and the broader tectono-geomorphological evolution of the Swiss Molasse Basin. A crucial part of this thesis bases on the application of models and quantitative approaches for simulating sediment fluxes. Amongst other parameters, the underlying concepts require information on grain sizes, which measurements build another important aspect of this thesis.