A radiometric timescale challenges the chronology of the iconic 1992 Guliya ice core.

The Guliya (Tibet) ice core drilled in 1992 (GP1992) has garnered special interest because of its exceptionally long timescale of ~760 thousand years. This timescale makes GP1992 currently the second oldest ice core in the world, much older than any other extrapolar ice cores. Here, we revisit the GP1992 timescale by dating a Guliya ice core (GP2021) that was drilled close to the GP1992 drilling site in 2021. All our data, including the absolute dates deduced from 210Pb, 39Ar, and 14C, confirmed an age of <3 thousand years at 175.1 meters depth of GP2021, compared with ~100 thousand years previously estimated at the stratigraphically equivalent depth in GP1992. Our results resolved several discrepancies between the GP1992 and other paleoclimate records in the region, leading to different insights in climate history of the Tibetan Plateau.