FOCUS: Luminescence dating of coastal sands: Overcoming changes in environmental dose rate

The luminescence dating of Pleistocene deposits produces erroneous ages if the radioactivity of the surroundings has changed over time. A subtraction procedure is described by which this problem can be overcome, if both the quartz and potassium feldspar minerals are analysed separately. The method is best used in cases where the external radiation is similar in magnitude to the internal dose rate of the feldspar. This approach has been applied to four sand deposits on the coast of South Africa that date to the beginning of the Late Pleistocene.