Current challenges to ESR dating

Electron spin resonance dating is applicable to a wide range of materials found at Quaternary sites, and which can generally be assured to exhibit zero signals at the time to be dated (t = 0). Local inhomogeneity in external dose rates may contribute to dispersion in apparent dates, but average dates may still be good estimates of site ages. Testing of U-uptake models by U-series measurements shows that both early and continuous uptake can occur, possibly even in the same site. Problems of signal lifetime determination and diagenesis are reviewed.