Automated SEM–EDS heavy mineral analysis reveals no provenance shift between glacial loess and interglacial paleosol on the Chinese Loess Plateau

摘要

Understanding provenance of glacial loess and interbedded interglacial paleosol deposits on the Chinese Loess Plateau (CLP) is important to understanding paleo-atmospheric circulation patterns. However, great debate exists about whether Chinese loess and paleosol deposits have similar provenance both spatially and temporally. Here we report heavy mineral assemblage results of two sets of loess–paleosol couplets (L1 and S1; L4 and S4) from western CLP based on scanning electron microscopy with linked energy dispersive spectrometers (SEM–EDS) analysis (QEMSCAN@). The results demonstrate no apparent provenance shift on the CLP between glacial and interglacial periods. Heavy mineral assemblage comparison between the western and the central CLP reveals no provenance shift spatially, either. Finally, a comparison of heavy mineral assemblage between loess–paleosol and potential source regions reveals that the western Mu Us desert, the Badain Jaran desert, the Ulan Buh desert as well as the Yellow river are likely key dust contributors for the CLP. In contrast, the northeastern Mu Us desert are less likely key dust sources for the CLP. The ultimate provenance history of the CLP relies no doubt on integrated provenance studies. However, due to its rapidity and robustness, integrated provenance analysis should incorporate the QEMSCAN-based heavy mineral analysis.