Fingerprinting sediment sources in the water-wind erosion crisscross region on the Chinese Loess Plateau

Sand sheet sources in the wind-water erosion crisscross region of the Chinese Loess Plateau have not been specifically identified. Spatially, we selected a transect that cuts across the eastern edge of the Mu Us Sandy Land, sand sheets distributed loess hills (sand-loess hills), loess hills, and adjacent rocky mountains to collect surface sediment samples. Temporally, we selected a site on a sampling sand-loess hill to collected depth incremental samples in a 320 cm depth soil profile to analyze sediment sources using the multiple composite fingerprinting approach. We screened out a group of optimal composite fingerprints that correctly classified sediment sources at 100%. Greater than half of all sediment on sand-loess hills originated from the sandy land area on the sampling transect, and roughly half from the sandy land in the soil profile, while the remaining sediment all originated from the loess hills, and rocky mountains had no contributing effect. Coarse particles (> 100 mu m) on sand-loess hills were mainly transported from the Mu Us Sandy Land, while fine particles were mainly from loess hills, indicating the importance of aeolian activity in the transport of sand from the Mu Us Sandy Land to loess hills. Environmental changes chronicled by sediment deposition at approximately 12.85 ka BP in the soil profile were primarily attributed to climate change. This study confirms that the composite fingerprinting approach is a feasible method for future studies on sediment sources in areas influenced by complex erosion agencies, landforms and soil types.