Abstract:

The Gobi Desert regions in northwest China with poor natural conditions and scarce resources are considered a gaping hole in prehistoric human evolution. But field investigations have revealed the presence of prehistoric human occupations and activities here, serving as important data for studying the late Pleistocene human migration and diffusion in China. However, these archaeological remains were predominantly discovered on the surface, lacking distinct geological layers, which makes it challenging to conduct comprehensive and detailed research including chronology.
Since 2020, we have carried out field surveys in the Alxa Plateau, and 7 new prehistoric hominin activity sites and 113 stone artifacts were discovered in the eastern edge of the Badain Jaran Desert. The stone artifact assemblages comprise 57 flakes, 10 cores, and 46 tools. And among tools, scrapers are the most numerous, while there is also a smaller number of bifaces, points, burins, choppers, and used flakes. These stone artifacts were all collected from the desert surface.
In the absence of an accurate burial age, we propose that the age of the layer below the stone artifacts is likely to be greater than or close to the age of hominin occupation, and can temporarily serve as a reference age for human activities. The optical stimulated luminescence (OSL) dating method was used to determine the age of the underlying strata. Two OSL samples were collected from the underlying sand layer at the MDLS-1 site and dated back to approximately 7.3±0.3 kaBP and 8.3±0.5 kaBP; while one OSL sample was collected from MDLS-3 site and dated back to approximately 9.4±0.4 kaBP.
Based on the distribution of the sites and the age of the underlying strata, it can be preliminarily speculated that the prehistoric populations may have occupied the seasonal river terrace in the Mandela Mountain area no earlier than 7.3 kaBP. Of course, we do not rule out the possibility that their occupation of the higher parts of the terrace began at 9.4 kaBP. In addition, the temperature and precipitation simulation (TraCE-21 ka) indicate that during this period, some areas of the Badain Jaran Desert had a relatively humid climate, abundant groundwater, and relatively high surface vegetation coverage, providing favorable conditions for the occupation and survival of the hunting and gathering crowds. This study is of great significance for understanding the hominin occupation and activities in the northwest Gobi and desert of China during the early Holocene.

Key words: Badain Jaran Desert, Mandela Mountain, stone artifacts, OSL