We propose a new method of cross-dating the wood samples based on the classical methods of spectral estimation. This method uses the average cross-spectral density as a function of the relative position of the series. Because it is not sensitive to phase shifts in data it is appropriate for cross-dating samples originating from geographically distinct areas.
The accuracy of cross dating depends on the integrity of the samples used, and in the case of well-preserved wood samples, the precision of relative age comparison may reach a single year. The method was tested on two dendrochronological series from Scythian barrows of known age in Southern Siberia: the Pazyryk barrows (the Altai Mountains) and the Dogee-Baary-2 burials (Western Sayan Mountains) separated by 450 km. The analysis has shown that the Pazyryk barrow is younger by 80 ± 4 yr than the Dogee-Baary −2 burials. This result is in agreement with the new chronology of Scythian-related sites suggested for Southern Siberia and Central Asia.