New evidence of prehistoric human activity on the central Tibetan plateau during the early to middle Holocene

The cold and hypoxic environment of the Tibetan Plateau was a major challenge for its prehistoric human occupants. The earliest known hominin occupation (or visitation) of the Tibetan Plateau was at ~200 ka, in the middle Pleistocene, and these hominins must have had survival strategies for this harsh environment. We report the discovery of 5 handprints and 17 footprints on the travertine near the outlet of the Quesang hot spring, a well-documented archeological site with well-studied hominin hand and footprints on the Tibetan Plateau. Based on ichnological analysis and U-Th dating, we found that these intentional and unintentional traces were impressed during the early to middle Holocene. Combined with the 19 previously-dated hand and footprints from around the hot spring, we conclude that this site was attractive to ancient humans who made repeated visits over a long period. The strengthened monsoon in the early and middle Holocene may have promoted the expansion of prehistoric human activity onto the central Tibetan Plateau. The frequent human activities near the Quesang hot spring imply that the widespread hot springs on the Tibetan Plateau provided resources that facilitated human survival in this cold and dry plateau region.