Sediment Grain-Size Composition in the Permafrost Region of the Greater Khingan Range and Its Significance as a Material Source

Sediment grain-size distribution (GSD) provides rich information about sedimentary sources and can potentially do the same with regard to environmental climatic changes. However, neither traditional descriptive statistics nor curving-fitting methods fully address its complexity. We selected Greater Khingan Range in northeastern China as study area used parameterized end-member analysis (EMA) of GSD four drilling cores extract different (EM) components. The results show that EM1 (mode particle size (Mo): 1.26–1.66 μm) originates from weathering pedogenesis. EMs Mo values 4.37–5.01 μm represent components transported by upper westerly wind. 7.58 11.48 wet dust deposition dry deposition. wind transport particles winter consists low-level near-source local-source (possibly flood plain Amur River). Due limitations EM model, two have one or components: AEM3 + AEM4, BEM3 BEM4, CEM4, DEM4. DEM5 is only large particle-size component may coarse-grained detritus generated via rock weathering. related monsoon 14C dating data suggest a weak-strong-weak-strong trend since Marine Isotope Stage 3a (MIS 3a). Our strengthening monsoons previous few thousand years has caused transportation coarser grain sizes further exacerbated permafrost degradation, providing scientific reference for understanding climate change formation evolution Mountains MIS 3a.