Geochemical characteristics of surface dune sand in the Mu Us Desert, Inner Mongolia, and implications for reconstructing the paleoenvironment

Abstract

We present a new dataset from 28 active and 13 stabilized–semi stabilized dunefields in the Mu Us Desert to report the geochemical macroscale properties as well as reveal the relationship between various chemical ratios and modern climate conditions among different types of Mu Us sandy landscapes. We find that several chemical-weathering indexes, such as CIA, CIW, CPA, and WIP, can be used for the reconstruction of the paleoclimate and servel conditions. One should be cautious in interpreting the weathering intensity using these chemical ratios at a given deposition site when the geochemical background is unknown. This preliminary geochemistry study shows that stabilized–semi stabilized dunefields, which are influenced by Asian summer monsoon (ASM) precipitation, are analogous to buried paleosols, whereas active dunefields, which are controlled by Asian winter monsoon (AWM) wind, resemble paleo-dune sand. The comparison with the geochemical results from an excellent dune−paleosol succession implies that stronger ASM and AWM periods could have recurred 8–9 times in the Mu Us Desert during the early Holocene.