Data to: Titanium, strontium and neodymium isotopic compositions of Lake Qarun sediments; assessing sediment provenance in the Nile and Ti isotope fractionation in the Nile Delta

We present Sr, Nd, and Ti isotope data from Nile sediments at Lake Qarun, along with Ti isotopic compositions from Nile Delta samples collected in Wadi Natrun. The Ti isotopic compositions of all sediments analysed range from +0.11‰ to +0.20‰ and average at +0.149 ± 0.015 ‰ (2SE, n=14). The 87Sr/86Sr ratios and Nd values of Lake Qarun sediments exhibit small variations and average at 0.70754 and -2.5, respectively. These radiogenic isotope signatures are characteristic for Nile sediments and plot in between those from the Nile in Sudan and the Nile Delta. Furthermore, the heavy Ti isotopic compositions of Lake Qarun samples match those of the Eastern Mediterranean Sea sediments. Therefore, Nile sediments carry a heavy 49Ti signature already before entering the delta, proofing that hydrodynamic mineral sorting within it is not responsible for the Ti isotope values of the Eastern Mediterranean Sea sediments. Instead, we show with trace element modelling that the proportion of felsic material transported in Nile sediments increases from the Atbara (3%) to the Blue Nile (22%) and reaches between 44% to 68% in the Nile Delta. These estimated proportions of felsic lithologies correlate favourably with Sr and Nd isotopes, suggesting that the observed variations in these isotopes along the Nile are primarily driven by the addition of felsic source rocks to the sediment load. The heavy Ti isotopic composition of Nile sediments entering the delta can be plausibly explained by a contribution of approximately 45% felsic rock material, derived from felsic Ethiopian Trap lithologies as well as from bedrock or sediments within the Nile catchment.