Abstract:

From 2021 to 2022, a joint archaeological survey was carried out in the Duilong River valley, Lhasa, Xizang, with the support of the Second Tibetan Plateau Scientific Expedition and Research Program. This collaborative effort involved researchers from the Institute of Tibetan Plateau Research, Chinese Academy of Sciences, and the Institute for Conservation and Research of Tibetan Cultural Relics. The main objective was to investigate prehistoric human activities in this high-altitude region, especially to identify Paleolithic sites buried in primary strata.

The survey area, located in the hinterland of the Tibetan Plateau at an average altitude of about 4,000 m, includes the Duilong River valley and its tributary systems. These river valleys have well-developed fluvial terraces, which not only serve as the location for modern villages but also as favorable areas for prehistoric human habitation. A total of 13 Paleolithic localities were discovered, consisting of 3 sites with primary buried deposits (Shanggagang, Qiusangsi, and Jiawu) and 10 surface lithic scatters. The elevation of these sites ranges from 3837 m to 4182 m, reflecting the adaptability of early humans to extremely high-altitude environments.

A systematic analysis of 79 stone artifacts shows a consistent technological pattern dominated by core-flake assemblages. The lithic industry lacks advanced products such as handaxes, blades, or microblades. In terms of the number of stone artifacts and well-preserved buried strata, Shanggagang and Qiusangsi sites are the two most important sites identified in this survey.

For the 54 stone artifacts discovered at the Shanggagang site, the raw materials were mainly igneous rocks (64.8%), followed by chert (16.7%) and quartz (11.1%), sourced locally from river gravels. Among the 7 cores, the classification includes discoid cores (n=4), polyhedral cores (n=2), and a bipolar core (n=1). The 27 flakes include 15 Type VI, 7 Type V, 3 Type III, 1 Type II, and 1 bipolar flake. The tool assemblage (n=12) is mainly composed of scrapers (n=11), with only 1 pointed tool identified. The number of stone artifacts discovered at the Qiusangsi site is relatively small, but all 5 stone artifacts were found in the primary strata. The raw materials of the 5 artifacts are all igneous rocks, and the knapping method used is the percussion method. The only core found is a polyhedral core. Among the two whole flakes, one is a Type V flake and the other is a Type VI flake. Unfortunately, no tools were discovered. Due to the limited number of stone artifacts found in this investigation, it is difficult to conduct comprehensive and in-depth research and analysis on the technological attributes and cultural connotations of the site.

Optically stimulated luminescence (OSL) dating of cultural layers at Shanggagang and Qiusangsi provided preliminary age estimates, indicating human occupation no later than 100 kaBP. However, signal saturation prevented precise chronological resolution.

The discovery of buried sites in the Duilong River valley significantly expands the geographical and temporal scope of known Paleolithic activity on the Tibetan Plateau. This survey confirms that humans inhabited the hinterland of the Tibetan Plateau at least by the Middle Paleolithic.

Future work should focus on formal excavations, refined chronometric methods, and comparative studies with adjacent regions to reveal the dynamics of early human colonization and adaptation on the Tibetan Plateau. This survey lays a crucial foundation for understanding the adaptability and creativity of Pleistocene hominins in the challenging environments of the Tibetan Plateau.

Key words: Tibetan Plateau, Xizang, Paleolithic Archaeology, Stone artifact