Abstract:
The Jingbian loess section is located in the transition zone between the loess plateau and desert, which is more sensitive than others to the Quaternary East Asian monsoon climate changes. The analyses of chronology, susceptibility, grain size and geochemical elements of the loess section in the south of Jingbian county were carried out. The Jingbian loess is a kind of eolian deposits composed of more than 80% of silty sand. Dating age suggests that there is a millennial scale sedimentary discontinuity in the section. The chemical data shows that the loess is in a primary weathering stage and the element abundance is in an order of Ca > Na > Mg > Si > Al > K > Fe. The comprehensive multi-index analyses suggest that the loess section has suffered four stages of climatic changes since the Last Glacial Period. The MIS3 was relatively warm, humid and oscillated. The Last Glacial Maximum was extremely cold and dry. The Last Deglaciation was under an improving climate condition and the Holocene warm and humid.