Dating the key structures of the Guge ancient city through integrated 14C and literary research

This study integrates AMS ¹⁴ C dating of 12 plant specimens, Bayesian modeling, and Tibetan texts to establish the first high-resolution construction chronology for key structures of the Guge ancient city in western Tibet. To ensure chronological precision and mitigate the old-wood effect, sampling prioritized short-lived annual plants and the outermost growth layers of small-diameter timber. Radiocarbon data were processed using the IntCal20 calibration curve and constrained by independent historical termini ante quos derived from mural inscriptions and prayer texts. The findings delineate three primary developmental phases: an Early Construction Phase (mid-to-late 15th century) encompassing the VIF27 complex, dated to 1457–1471 CE; a White Temple Phase (mid-16th century) focused on Buddha statues, which ended between 1556 and 1560 CE; and a Late Defensive Phase (mid-17th to late 18th century) involving the reinforcement of Watchtower VIII D2 (1661–1813 CE), possibly in response to regional conflicts. Notably, the use of herbaceous samples successfully resolved the 16th-century calibration plateau ambiguities, aligning the production closely with the reign of King Jig rten dbang phyug. This systematic framework provides a robust empirical foundation for understanding the architectural evolution and socio-political transformations of the Guge Kingdom.