Heinrich events recorded in a loess–paleosol sequence from Hexigten, Inner Mongolia

We describe the last glaciation climatic history Marine Isotope Stage (MIS, 2–4) from 66.7 ka to 14.5 ka in Hexigten, northeast Inner Mongolia, North China. The climate of the region experienced frequent and significant fluctuations between dry-cold and less dry-cold during the late MIS4. The climate was generally warm and humid during early MIS3 (MIS3c) and late MIS3 (MIS3a), whereas it was cold and dry in middle MIS3 (MIS3b) and during MIS2. In this study, the cold and dry conditions were correlated with a stronger East Asian winter monsoon and strong dune activity; whereas, warm and humid conditions were related to a stronger East Asian summer monsoon (EASM) and weak dune activity. This study establishes six distinct dry and cold intervals during the last glacial period (66.7–14.5 ka) based on optically stimulated luminescence data, multi-proxies record (magnetic susceptibility, grain size analysis, Rb/Sr, SiO2/TiO2) and chemical index of alteration (CIA). The last glacial period may be correlated with Heinrich events 1 to 6 which were further confirmed by comparison with the Hulu cave stalagmites and Greenland ice core records. It is concluded that the study area was substantially affected by the EASM, as compared with the loess–desert transition zone of the Chinese Loess Plateau, especially in MIS3c and suggested that the East Asian monsoon played a pivotal role in the last glacial period climate and dune activity.