Distributions of lead isotopes with grain size in aeolian deposits

Abstract

Lead (Pb) isotopes are a powerful tool for identifying aeolian dust sources and reconstructing atmospheric circulation patterns. However, the grain-size dependence of Pb isotopes has not been well documented. This study demonstrates the grainsize effect on the Pb isotopes in four loess samples and one contemporary dust fall sample. The results indicate that the Pb isotopes show significant variation with grain size with no specific trend for all types of aeolian deposits. The Pb and neodymium (Nd) isotopes with grain-size fractions indicate that the potential sources of aeolian deposits from the Sichuan Basin, the Chinese Loess Plateau and the Tibetan Plateau probably differ from one another.