Multi-parameter cross-dating: using isotope analysis to extend tree-ring chronologies (foreign research data)

Dendrochronological analysis is a fairly effective method of dating historical wood; however, it is not without significant limitations. This is particularly evident in considering the early segments of tree-ring chronologies, where both availability of historical wood and the amount of chronological curve overlaps are insufficient. Inclusion of incorrectly dated tree-ring series incorporated into an overall chronology can result in significant errors. In light of these considerations, only samples with high dating confidence are typically included in concluding research data; this situation results in the exclusion of some undated wood from scientific circulation. Recently, in addition to chronologies based on annual ring width (TRW) and maximum latewood density (MXD), a new promising method of dating living and historic wood has been proposed: by stable oxygen and carbon isotopes contained in tree rings. The initial findings of these studies have indicated that it is feasible to align data not only between trees of the same species growing in a common area, but also between trees of disparate species. Furthermore, the method of high-precision radiocarbon dating based on objective time markers, known as ‘Miyake events’, is being successfully developed. In 2023, a team of authors from Germany and the Czech Republic conducted unique research that combined all modern cross-dating methods, namely the use of several parameters simultaneously, including TRW, MXD, SI3C and I4C. The researchers used combined stable carbon isotope (SI3C) and radiocarbon (I4C) data in estimating and correcting dating errors in the initial segments of the longest tree-ring chronology generated for the highlands of the Mediterranean Basin. The findings provide compelling evidence that integrating TRW chronologies with SI3C measurements facilitates considerably more reliable dating of uncertain and poorly correlated sections of the chronologies.