Various wind activity proxies unmixed from grain-size distributions of surface eolian sands at the desert scale in the Tengger Desert, Northwest China

Abstract

Reconstructing wind activity strength enhances our understanding of desert evolution and environmental changes. Unmixing the grain-size components from eolian sands can serve as a proxy for wind activity in deserts. However, the links between the grain-size components of eolian sands and the strength of wind activity throughout the desert have rarely been explored. In this study, 81 surface eolian sand samples were analyzed from flat sandy areas or interdunes across the Tengger Desert in northwestern China, each with a similar depositional environment. The three grain-size components were separated from the samples using a parametric end-member mixing algorithm (EMMA). Based on their grain-size distribution characteristics, the three end-members (EMs) represent transport processes affected by various wind forces, including the East Asian winter monsoon (EAWM, EM1), local wind (EM2), and sandstorms (EM3). Additionally, the content of EM1 and the 63–158 μm components both showed significant positive correlations with EAWM indices, whereas the content of EM3 exhibited a significant negative correlation with the strong wind frequency (SWF). Therefore, these three new proxies (EM1, 63–158 μm components, and EM3) hold significant relationships with the wind activity indices, aiding in the quantitative reconstruction of paleo-wind activity strength in the drylands. This study enhances our understanding of the relationship between sedimentary proxies and wind activity strength, contributing to our knowledge of dryland eolian deposits and paleoenvironmental changes.