Reassessing the reliability of U-Th dating for the Quesang hand- and footprints

Since its publication in 2021, the discovery of hominin hand- and footprints at the Quesang site on the Central Tibetan Plateau has attracted widespread attention and sparked intensive discussion within the archaeological community. The site preserves evidence of human activity from both the Middle Pleistocene and the Early-to-Middle Holocene, which serves as a critical milestone for understanding how humans expanded into and permanently occupied high-altitude extreme environments. Given the ongoing controversies regarding the chronology of the Quesang prints, this study presents a systematic review of the formation mechanisms of thermogenic travertine and its associated geochronological methodologies applicable to such deposits. Furthermore, we conducted a series of supplementary experiments to rigorously address and evaluate the major concerns raised regarding the reliability of previous age determinations. Our results demonstrate that the U-Th ages obtained from the Quesang travertine are robust and reliable, and are fully consistent with the available geochemical, petrographic and stratigraphic evidence. These findings provide strong support for the established chronology of the Quesang hand- and footprints and reinforce their significance for understanding early human occupation of the Tibetan Plateau.