Fidelity of the ²¹⁰Pb dating method, a subaquatic sediment perspective

In recent decades, ²¹⁰Pb has been extensively used as a powerful dating and sedimentation rate-determining tool for sediments deposited over the past ~150 years. However, the conditional assumptions underlying this application have not been explicitly validated, and are always challenged by multiple factors. Here, we synthesize all the possible factors that may limit the accuracy of ²¹⁰Pb as a geochronometer and bring together related evidence from observations, measurements, and sediment records. It was demonstrated that by affecting the initial ²¹⁰Pb activity and challenging closed deposition system, particle affinity preference, physical/biological mixing, sedimentation events, and ²¹⁰Pb post-depositional mobility are the four main contributors to its compromising accuracy. By systematically deepening the knowledge of the ²¹⁰Pb dating method, this study highlights the necessity of testing the assumption before using it, provides a framework for interpreting non-steady-state accumulation profiles from various sediments, and identifies future research opportunities for chronology improvement and ²¹⁰Pb application development.