First U-Pb dating of Kromdraai cave in the Cradle of Humankind UNESCO World Heritage Site

Kromdraai, a fossil-bearing site within the UNESCO World Heritage area known as the “Cradle of Humankind” (Gauteng, South Africa), has yielded numerous hominin remains, including the Paranthropus robustus holotype. Yet, it remains the only major site in the Cradle of Humankind lacking absolute dating. We obtained the first absolute dates for a key breccia block from Kromdraai, using uranium-lead geochronology. Uranium-lead methods have been applied across the Cradle of Humankind, typically yielding high-precision ages. However, their accuracy can be questioned when regression models provide a poor fit to isotopic data. By integrating multiple mathematical approaches, we derive age constraints for the block from 1.94 ± 0.08 to 2.67 ± 0.17 Ma, thus providing an initial chronological framework for future interpretations of the Kromdraai fossil record. Furthermore, we demonstrate that applying alternative mathematical approaches enables individual speleothems to be dated according to their best-fitting models, improving the robustness of chronological interpretations.