Pleistocene environmental evolution in the Nihewan Basin and implication for early human colonization of North China

The fluvio-lacustrine sequence in the Nihewan Basin is an important archive of Pleistocene climate and environmental changes in northern China, which provides excellent sources of early human settlements in high-latitude East Asia. Here a long-term environmental record from the Pleistocene fluvio-lacustrine sequence in this basin is revealed, based on selected major element pairs that are sensitive to paleoenvironmental changes. Results reveal a long-term increasing trend in aridification/cooling in the Nihewan Basin since the early Pleistocene. This provides a general setting for early human colonization in high-latitude northern China (around 40° N). The intensified aridification/cooling is envisaged to reduce tree cover and increase open savanna grass area. This, in turn, would promote prominent flourishing population and migration of savanna-adapted early humans in the Old World. Therefore, the cold/dry climate may have contributed to the evolution and expansion of early humans in the high-latitude northern China, rather than bringing hardship, as is often thought.