Inferences from geochemical characteristics of the upper part of the Middle Pleistocene interglacial deposits in Lithuania

The article presents geochemical characteristics of the Middle Pleistocene interglacials stratotype sections: two from the Butėnai Interglacial and two from the problematic Snaigupėlė Interglacial. Geochemical data (the contents of 29 chemical elements, percentages of sediment components) are related to magnetic susceptibility (MS), bedding, lithology and previous palaeobotanical results. Higher content of carbonates and clay in sections of the Snaigupėlė Interglacial can be explained by warmer climate and calmer depositional environment, though the influence of chemical composition of the underlying tills is also obvious. The influence of oxic-anoxic sedimentary environment fluctuations on MS and on the separation between P-Fe and S-Mn is demonstrated. Many geochemical differences between deposits from the intervals of the Snaigupėlė-705 borehole and the Snaigupėlė outcrop sections which presumably include pollen zone S6 Carpinus-Quercus enable the authors to speculate that these deposits were formed during different interglacials.