Alluvial Sediment Sources in a Glaciated Catchment: The Voidomatis Basin, Northwest Greece

This study investigates sediment source changes in the Voidomatis River Basin of northwest Greece during the late Quaternary by analyzing the fine matrix component of alluvial units and modern channel sediments using X-ray diffraction (XRD). The objective was to reconstruct sediment load composition and understand how these sources have evolved over time. We conducted XRD analysis on four alluvial units and found that the matrix fraction of modern channel sediments predominantly derives from local flysch rocks and soils, contrasting significantly with the last glaciation period when glacially-ground limestone materials dominated the fine sediment load. This research combined XRD work with a clast lithologic analysis program to assess the lithological properties of coarse and fine sediment elements across time. Results indicated marked variations in the composition of sediment loads during the late Quaternary. The methodology of assessing fine sediment mineralogy through diffractogram peak-height data proved complementary to traditional clast lithological techniques. Ultimately, our findings suggest that in suitable geological contexts, combining fine fraction mineralogy with clast analysis is a valuable approach for reconstructing late Quaternary alluvial environments.