Climate change in arid central Asia since MIS 2 revealed from a loess sequence in Yili Basin, Xinjiang, China

Abstract

K-feldspar pIRIR dating was used to establish a chronological framework for the KS15-05 loess section in the Yili Basin, northern Xinjiang Province, China, in arid central Asia. The reliability of the dating results was verified from the luminescence characteristics and internal checks. The chronology was used to calculate mass accumulation rates (MARs) for the section and the paleoclimatic proxies of grain size and magnetic susceptibility were also analyzed. The high dust accumulation patterns during the last glacial maximum in Yili Basin are consistent with those of the Chinese Loess Plateau (CLP). On a millennial-scale, the Bølling-Allerød (B/A) interstadial is clearly reflected in the KS15-05 section by the variation of the 2–10 μm grain-size fraction, suggesting the influence of the Westerlies which dominate the modern atmospheric circulation of the region. However, the B/A interstadial is poorly recorded in grain-size records of the CLP and this disparity may provide additional information about the nature of the transmission of climate signals from the North Atlantic region to Asia. Specifically, the zonal transmission of the B/A warm signal to the CLP may have been obscured by the cooling effect of High-latitude cold air to the north of the CLP.