Temperature Effects in ESR Spectra of Radical Centres in Dripstone Calcite Samples Used for ESR Dating

Natural calcite samples were collected from the dripstone layers of the Black Cave of the Tatra Mountains. ESR spectra, thermal analysis, and thermoluminescence data were analysed to obtain a consistent picture of the calcite properties. The ESR spectra were analysed using computer enhanced resolution spectra and an influence of the thermal annealing on intensity of individual ESR lines was measured. These results together with the effects of γ-irradiation in ESR spectra allowed one to discriminate between ESR lines from various paramagnetic centres. A general conclusion of the paper is that in the ESR dating the outer ESR lines of CO$\text{}_{3}^{-}$ (g=2.0125) and CO$\text{}_{2}^{-}$ (g=1.9980) radicals should be used instead of the commonly used multicomponent central line.