Late Quaternary evolution of river Nile at Wadi Kubbaniya, Egypt: Insights from mineralogy and geochemistry proxies

To reconstruct sediment provenance and assess related palaeoclimatic conditions, this paper integrates mineralogical and geochemical analyses of Late Quaternary sediments from Wadi Kubbaniya, northern West Aswan, Egypt. Bulk geochemical analyses and heavy-mineral assemblages indicate a diverse sediment supply primarily from Precambrian African sources, mainly via the Nile River, along with contributions from Nubian Sandstone and aeolian deposits. The geochemical characteristics highlight significant influence from source regions and extensive sediment recycling in the East African Highlands. Ultrastable minerals, especially zircon, tourmaline, and rutile, predominate in the heavy-mineral assemblage, leading to high ZTR index values that indicate compositional maturity, hydraulic sorting, and extended sedimentary reworking. These mineralogical fingerprints indicate a combination of locally produced lithological inputs from the surrounding desert landscape and mixed sediment contributions from the Blue Nile, White Nile, and Atbara systems. According to palaeoclimatic interpretation, floodplain and wetland environments developed in the lower portions of Wadi Kubbaniya during the Middle Paleolithic due to humid conditions and increased Nile flooding, while stabilized sand dunes occupied the comparatively higher areas. Widespread dune formation was subsequently stimulated by a trend toward increased aridity. Hyper-arid circumstances caused dune activity to resurface at the end of the Middle Paleolithic and during the Late Paleolithic, periodically damming the wadi and establishing transient lake settings. These dune barriers remained in place during the most recent Pleistocene until a remarkable flood known as the "Wild Nile," which occurred between 13 and 12 ka BP, broke through the natural dams and left behind large amounts of floodplain sediments.