Ages of fossil bones from British interglacial sites

THE time gap between the upper limit of radiocarbon dating (≈60,000 yr BP) and the lower limit of dates generally obtainable using the K–Ar method (≈250,000 yr BP) accounts for the scarcity of dates for the last two interglaciations (the Ipswichian and Hoxnian of Britain; the Eemian and Holsteinian of northern Europe). Accordingly, the ages of such important fossils as the Swanscombe and Steinheim skulls can only be guessed at. For that reason, the adaptation of a method that may date these interglacial periods is highly desirable. We discuss here the application of a uranium-series dating technique pertaining to that span of time.