Geochemical characteristics of surface aeolian sand in the Badain Jaran Desert, northwestern China: Implications for weathering, sedimentary processes and provenance

[Display omitted] •New geochemical data of dune sands in the Badain Jaran Desert are presented.•Geochemical features of desert sand are a provenance rather than a weathering proxy.•Qilian Mts. are the primary source of sand in the Badain Jaran Desert. Knowledge of the provenance of the aeolian sand in deserts is crucial for revealing their development and the corresponding driving mechanisms. As the second-largest desert in China, the Badain Jaran Desert (BJD) has developed the tallest megadunes on Earth. However, the material source of these dunes, especially the provenance of different particle size fractions, is debated. Here, we address these issues using new geochemical data, consisting of the major, trace, and rare earth elemental signatures of different particle-size fractions of dune sands in the BJD and sediments from potential source areas. The source area sediments are from the rivers originating in the Qilian Mts., the Gobi regions between the Heihe River and the BJD, the piedmont of the Gobi-Altay Mts., and the alluvial fan of the Beida Mts. The results show that the dune sands of the BJD are mainly derived from felsic source rocks subjected to weak chemical weathering in the source area. The fine fraction (