Grain Size Distribution in the Subsurface Sediments of Floodplains Across the Yukon River Basin, Alaska, 2022

To characterize the sedimentological properties of riverbank materials in the Yukon River Basin, we analyzed grain size distributions from bank sediments collected at two representative sites: the Koyukuk River near Huslia and the Yukon River near Beaver. These locations, situated within discontinuous permafrost regions, were selected to capture spatial variability in depositional environments and inform interpretations of fluvial processes, sediment transport dynamics, and sediment-associated carbon cycling in high-latitude floodplains. In addition to their geomorphic relevance, these sediments serve as reservoirs for organic carbon and potentially toxic elements, such as mercury. Associated organic carbon data are reported in Ke et al. 2024, doi.org/10.18739/A22R3NZ79, and mercury concentrations are archived in Isabel et al. 2023, doi.org/10.18739/A2WW7720N. As part of a National Science Foundation (NSF)-funded effort to assess erosion and biogeochemical cycling in the Yukon River Basin, sediment samples were collected between June and September 2022 from the Yukon River near Beaver (65.700 degrees North (°N), 156.387 degrees West (°W)) and the Koyukuk River near Huslia (66.362 °N, 147.398 °W). Grain size distributions were analyzed using laser diffraction analysis with a Mastersizer 3000E, and are reported here as statistical summaries.