Spatial variations in the provenance of eolian deposits on the Mu Us desert and the Chinese Loess Plateau

Whether the provenance of eolian deposits on the extensive Chinese Loess Plateau (CLP) is spatiotemporally heterogeneous/homogeneous is highly controversial. Here we present detrital zircon U-Pb ages for the eolian dust from the central-eastern Mu Us desert, its underlying Cretaceous sandstones, and the loess from the northeastern CLP. The comparable detrital zircon U-Pb age signatures between the eolian deposits from eastern Mu Us and Cretaceous sandstones suggests that eolian deposits in the eastern Mu Us are largely the product of weathering and recycling of regional bedrock. Typical loess on the northeastern CLP show relatively consistent zircon age spectra with those from the eastern Mu Us, indicating significant contributions of the western North China Craton (NCC) to the loess on the northeastern CLP. Temporal consistencies of U-Pb age spectra for a 13.6 m-thick eolian sand-loess sequence in the eastern Mu Us desert reveals that there is no apparent provenance shift at least since the last interglacial. Comparison of detrital zircon U-Pb age spectra of Late Pleistocene loess developed on the northeastern, eastern, and west-central CLP demonstrates that the contributions from the western NCC increase significantly for the loess on the eastern-northeastern CLP, while the west-central CLP received more eolian dust from the northeastern Tibetan Plateau (NTP) and the Central Asian Orogenic Belt (CAOB). The contribution of detritus from the NTP decreases, and the contribution from the western NCC outweighs that from the NTP on the eastern-northeastern CLP. Our new detrital zircon data provide robust evidence for the spatial heterogeneity of provenance across the CLP, regardless of the general characteristics of multiple recycling and thorough mixing of Chinese loess.