Evidence from the Dayao Paleolithic site, Inner Mongolia for human migration into arid northwest China during mid-Pleistocene interglacials

Abstract

The Dayao Paleolithic site, located in Inner Mongolia on the eastern margin of China's vast northwestern drylands, was a lithic quarry-workshop utilized by Pleistocene human migrants through the region. Determining the age of this activity has previously yielded controversial results. Our magnetostratigraphic and OSL dating results suggest the two artifact-bearing paleosols are correlated with MIS 5 and 7, respectively. Correlating paleoclimatic data with marine δ18O records leads us to conclude that two sandy gravel layers containing many artifacts in the lower part of the Dayao sequence were formed during MIS 9 and 11, if not earlier. Our results reveal that the earliest human occupation at the Dayao site occurred before ca. 400 ka during a relatively warm and moist interglacial period, similar to several subsequent occupations, documenting the earliest and northernmost archaeological assemblage yet reported in China's arid northwest. We conclude that the northward and southward displacements of the East Asian summer monsoon rain belt during past interglacial-glacial cycles were responsible for the discontinuous human occupation detected at the Dayao site. The penetration of this precipitation regime into dryland ecologies via the Huanghe (Yellow River) Valley effectively created a corridor for hominin migration into China's arid northwest.

Glacial–Interglacial Cycles and Early Human Evolution in China

“…The key factor lies in understanding the cold resistance of hominins [215]. There is no denying that hominin occupation in northern China usually occurred during warm and humid interglacial periods, e.g., [98,189]. Warm clothing, storable food, and the use of fire were important conditions for over-wintering [246].…”

Eurasian environmental dynamics and humans: interactions over different time scales

“…The research suggests that the area close to today's Petrovaradin Fortress was already inhabited in MIS 5, and the relative environmental stability during the last glacial period is likely also a key factor in human occupation. Ge et al (2021, this volume) conducted a chronological and environmental study of the sediment sequence at the Dayao Paleolithic site in Inner Mongolia on the eastern margin of China's vast northwestern drylands. With constraints from evidence of magnetostratigraphy, OSL dating, and overlying paleosols, climatostratigraphic correlation suggests that two sandy gravel layers containing abundant artifacts in the lower part of the Dayao sequence were formed during MIS 9 and 11.…”