Quaternary dust source variation across the Chinese Loess Plateau

The Chinese Loess Plateau in north central China contains one of the most valuable Cenozoic climate archives on land. Establishing the origin of this substantial archive of aeolian sediments is critical for the interpretation of loess climate proxies, past atmospheric wind patterns and changing climatic/tectonic controls on erosion over potentially the past 25. Ma. Despite this significance there are a number of disagreements over the precise source areas and the extent to which these vary through time and across the plateau. To address this, we utilize a multi-technique, approach of combined detrital single-grain zircon U-Pb dating and heavy mineral analysis to establish the sources of loess through the Quaternary and constrain their variation geographically across the Loess Plateau. We combine our data with suitable published single-grain datasets from loess and possible source regions. The results demonstrate a dramatic spatial heterogeneity of dust sources across the plateau. Sites to the west of the Loess Plateau show strong affinity to the Yellow River and the northern Tibetan Plateau, while further east the influence of North-China-Craton-derived material becomes more significant (Fig. 1). This spatial variability in source implies a far more complex relationship to dust sources than previously envisioned. The provenance of loess/soil units also varies through time, although there is no consistent relationship between these shifts and changing glacial/interglacial periods, as hypothesized previously. This variation demonstrates highly dynamic and variable dust sources and transport modes that are influenced by abrupt climate shifts within individual glacial-interglacial episodes, and potentially the dynamics of the Yellow River system.