OBSERVATIONS ON SOME THERMOLUMINESCENCE EMISSION CENTERS IN GEOLOGICAL QUARTZ

We report measurements of three-dimensional thermoluminescence emission spectra of samples of geological quartz, derived from Australian sediments. The emphasis is on peaks of particular practical interest for thermoluminescence sediment dating, viz. the 110 degrees C peak, which is used for pre-dose dating and the peak at 325 degrees C, which is of significance of partial and selective bleach techniques and for optically stimulated luminescence (OSL) dating. Because the 325 degrees C peak can be bleached to essentially zero, it can be isolated in a given spectrum by subtracting the bleached spectrum for the unbleached spectrum. By including both peaks in the same spectrum, it is demonstrated that they do not emit at the same wavelength, although this does not necessarily mean that the emission is from different emission centres. The 375 degrees C peak, which is important in total bleach methods, emits at a distinguishable wavelength. The use of bleaching and subtraction in practical dating is discussed.