Sample quality index to preselect suitable carbonate samples for alpha spectrometry U/Th dating

Accurate dating of samples by alpha spectrometry presupposes that the dated system behaved as closed and that no allochthonous 232Th was provided to the system. Therefore the selection of appropriate samples is a fundamental task that will determine the reliability and accuracy or not of the results. In this paper, by means of a thorough characterisation, those petrological and chemical variables that allow the preselection of the most suitable samples to be dated have been identified and used to calculate the sample quality index. - Highlights: ► Twenty thermogene travertine samples have been dated by means of the U/Th method. ► A mineralogical, petrographic and chemical characterisation was previously performed. ► A screening method is proposed based on a statistical analysis. ► 4 variables have been used to preselect the most suitable samples to be dated. ► A numerical index has been developed to quantitatively show the suitability of samples