Cross-check of the dating results obtained by ESR and IR-OSL methods: Implication for the Pleistocene palaeoenvironmental reconstructions

Abstract

The consistency of the dating results obtained by different methods, both absolute and relative, is investigated. The main absolute methods referred to in this article are the mollusc-based electron spin resonance (ESR) and feldspar-based infrared optically-stimulated luminescence (IR-OSL) dating methods used in the Research Laboratory for Quaternary Geochronology, Tallinn University of Technology. It was shown that the parallel comparative dating by these two methods yield, essentially, consistent results. U–Th age determinations were performed in some cases for better understanding of the uranium behaviour in the shells during their burial history. ESR and U–Th dating results obtained on one and the same shell-type, both marine and land snails, coincide well in the case if shells behaved as a close system during their burial history. It is also shown that the numerical dating results obtained on warm and cold climate-related deposits, correlate well with the corresponding palaeoclimate signals derived from continuous records of the climate and environmental evolution, constructed on the base of the most common of the relative dating methods used in Quaternary studies. Based on good consistency of the results obtained by all methods used in the present comparative study, we conclude that there is a good potential to improve our understanding of the middle to late Pleistocene palaeoenvironmental evolution in Northern Eurasia, with a special focus on the climatically highly sensitive Eurasian Arctic palaeo-shelf area.