High-precision (81)Kr dating overcomes radiocarbon limits in Late Pleistocene groundwater.

High-precision 81Kr dating extended the effective lower limit to ~10 ka in Late Pleistocene groundwater, enabling coverage of the entire Late Pleistocene archive.

• Why it matters: Groundwater can preserve continental hydroclimate signals, but radiocarbon dating is limited by carbon geochemical uncertainties, and 81Kr previously had an effective limit of ~50 ka.
• What they did: Using high-precision atom trap trace analysis, the authors pushed the 81Kr lower limit to ~10 ka and performed a direct 14C–81Kr comparison in North China Plain groundwater.
• The result: In the 10–30-ka interval, 81Kr independently validates 14C ages, while beyond that range it provides reliable ages for older groundwater and supports δ18O matches to polar ice-core records.

AI summary of the abstract · may contain errors · not medical advice · read the paper.