Late Middle Pleistocene interglacial sediments from Buivydžiai site, eastern Lithuania: A problem of chronostratigraphic correlation

A number of interglacial sections discovered in the eastern part of Lithuania and suggested as Snaigupėlė Interglacial were attributed to the Saalian Complex Stage of Middle Pleistocene. However, the exact stratigraphical position and correlation of these interglacial sections are still arguable. Recent investigations were performed to get a clearer insight into the stratigraphy and sedimentation palaeoenvironment of the Snaigupėlė Interglacial sediments outcropping in Buivydžiai section and included complex proxies: pollen, plant macrofossils, diatoms, loss on ignition, magnetic susceptibility and optically stimulated luminescence dating. Interglacial sediments occur at the lowermost part of the exposure and reach more than 7 m thick. Palaeobotanical investigations confirm deposition of studied sediments during the different climatic stages of the interglacial. An attempt at correlation between the Buivydžiai section vegetational changes with vegetational succession obtained from north-central Europe allowed finding out some similarities with the Schoningen/Lublinian Interglacial. The OSL dating results do not contradict such a proposition as the two sand samples lying below the interglacial gyttja show sedimentation of this layer during the 300.5 ± 20.9 ka and 317.3 ± 21.8 ka time or MIS 9. However, recently obtained data are insufficient for grounding the correlation of studied section. Certainly, additional chronostratigraphic investigations would be valuable and may contribute to the solution of the sediment age and correlation problem.