Testing heated flint palaeodose protocols using dose recovery procedures

Abstract Thermoluminescence (TL) dating of materials from archaeological contexts has been shown to be an accurate method when comparisons are made with other chronometric dating methods; however, little has been published on the verification of the measurement protocols used to determine the equivalent dose (palaeodose). Instead of testing TL dating protocols for heated flint using archaeological material with unknown thermal and radiation history, dose recovery tests for three samples of different geological origin are presented. These samples exhibit TL emission in the UV, blue and orange–red wavelengths. In addition to the two multiple aliquot protocols (standard additive-regeneration and normalization) generally used to determine the palaeodose, the single-aliquot-regenerative-dose (SAR) TL and OSL procedure, a ‘short’ SAR–TL and isothermal luminescence (IT) decay procedures are applied using detection windows limited to these emissions. Accurate dose recovery is obtained for the standard and normalization protocols in the commonly employed detection window (UV-blue), the ‘short’ SAR in the orange–red window and some IT measurements. While the standard techniques give the most accurate and precise results, detection of the TL and IT orange–red emission in connection with a ‘short’ SAR protocol also gave accurate and precise results. Such procedures are especially suitable for samples too small for standard multiple aliquot techniques, which require large samples.