Geochemical evidence of the Chinese loess provenance during the Late Pleistocene

The provenance of Chinese Loess Plateau sediments is an often-posed question that has not been satisfactorily resolved. Elemental geochemistry characteristics of the deposition may provide important evidence in this regard. To this end geochemical analyses were undertaken on densely sampled strata from four loess sections (one of which is located in Northwestern China at the desert margin and the other three on the Loess Plateau) as well as sediments from the Badain Jaran Desert. It was found that loess deposition on the Chinese Loess Plateau and the northern foot of the Qilian Mountains had strong geochemical similarity during the last glacial cycle, but had remarkable differences with the Badain Jaran Desert samples. It is inferred that the desert was not the most important direct provider of dust material to the Loess Plateau. Rather, one of the main source areas appears to have been the vast silt-rich piedmont alluvial fan distributed at the northern foot of the Qilian Mountains.