Contributions of Asian dust to subtropical soils of Southeast China based on Nd isotope

Purpose China is not only a main source area of Asian dust but also a significantly affected area of dust deposition in the world. However, the influence range of Asian dust deposition and its influence on soil provenance remains unclear, particularly in subtropical regions. This study identified the substantial effect of Asian dust on soils and quantified its contribution to subtropical soils of China. Materials and methods Three soil profiles derived from basalt in subtropical area (Shaoxing, Zhejiang, China) were selected and sampled. The pH, bulk density, and cation exchange capacity (CEC) of soils were determined. The Neodymium (Nd) and Thorium (Th) concentrations and Nd isotope of soils were determined. We used the Nd elemental and isotopic geochemistry to assess the deposition of Asian dust in soil profiles (up to 1 m depth). Results and discussion The upper soil layers have negative epsilon(Nd) (0) values, which were close to those of Asian dust epsilon(Nd)(0) = -3.30), indicating the input of Asian dust to soils. Further, the high dust-derived Nd proportion in the soils (f(dust)(Nd) = 43%) also suggested a great contribution of Asian dust on soils. A comparison of Nd in the soils from subtropics (Zhejiang province, Southeast China) and tropics (Hainan province, China's southernmost point) indicated that both regions were influenced by Asian dust but at different degrees. Conclusions Asian dust has been identified as a vital source of Nd in subtropical soils of China. The high mass fraction of dust-derived Nd in the soil profiles indicated the important role of dust input in soil genesis. The results also suggest that Nd isotopes are powerful fingerprints in tracing the origin of soil materials.

Automated summary

The study found that Asian dust significantly contributes to subtropical soils in China, with a high mass fraction of dust-derived Nd in the soils. Nd isotopes are powerful fingerprints in tracing the origin of soil materials.