A method for identification of interfering signals in EPR dating of tooth enamel

In this paper, a method for identifying interfering EPR signals in fossil tooth enamel is presented. This method consists of optimizing EPR parameters to enhance spectral resolution of the fossil signals followed by a g-factor and intensity normalized subtraction of a high-dosed, modern tooth enamel sample spectrum. By scanning the modern tooth enamel sample with the same parameters as the fossil sample, the difference spectrum of the fossil and modern irradiated tooth enamel samples can resolve numerous hyperfine and other interfering signals. This method was successfully applied to a fossil sample studied elsewhere (Grün, R., 1998a. Ancient TL 16, 51–55; Grün, R., Clapp, R., 1996. Ancient TL 14, 1–5; Martin Jonas, 1997. Ph.D. Thesis, Cambridge University; Jonas, M., Grün, R., 1997. Radiat. Meas. 27, 49–58; Vanhaelewyn et al., 2000. Appl. Radiat. Isot. 52, 1317–1326). This sample has shown discrepancies in dose estimations obtained from the power absorption curve versus those obtained from the first derivative spectra (Grün, R., 1998b. Radiat. Meas. 29, 177–193). The reason for this, and other discrepancies, are accounted for by the signals resolved using the method presented here.