Interglacial Quaternary Sediments as Possible Natural Source of Anomalies of Harmful Chemical Elements in Lithuania

Based on the geochemical results of interglacial Quaternary sediments in Lithuania obtained during implementation of the project “CIKLAS” the possibility appeared to study if these sediments can be a natural source of 10 potentially harmful chemical elements: As, Ba, Cr, Cu, Mn, Mo, Ni, Pb, V, Zn. Total contents of Ni, Cu, Pb, Ba in all analysed samples were lower than maximum permissible concentrations MPC for soil, of Zn, V, Cr, Mn exceeded MPC values in not more than 4% of samples. The highest percentage of anomalous samples where MPC was exceeded was characteristic of Mo (21%) and As (12.6%) indicating that interglacial sediments enriched in organic matter comprise one of the possible natural sources of Mo and As anomalies in stream sediments of Lithuania

Sedimentary environment changes during the Early-Middle Pleistocene transition as recorded by the Daumantai sections in Lithuania

Two sections (Daumantai-1 and Daumantai-3) in East Lithuania expose Early-Middle Pleistocene lacustrine-alluvial, deposits which lie on a thin Neogene layer and on older Devonian rocks. They are overlain by glacigenic deposits. Geochemical, palaeomagnetic, magnetic susceptibility, plant macrofossil, and diatom investigations were performed to determine the changes in the sedimentary environment. Cluster analysis of the geochemical variables (10 major elements, 16 trace elements, total organic and inorganic carbon) revealed the element groups and factors. The lowermost units are characterized by a major influence of local material and significant fluctuations in heavy mineral content. These fluctuations might reflect short-term climate changes. The transitional units have more expressed trends, especially as regards the trace elements and Zr/Ti. The uppermost units are characterized by a slight influence of local material and small fluctuations in trace elements. The data analysed enable the subdivision of the section into units related to changes in sedimentary environment. The boundary of the Bruhnes/Matuyama reversal in the Daumantai-1 and Daumantai-3 sections was detected by palaeomagnetic studies and enables the stratigraphical correlation of these deposits

The earliest Pleistocene interglacials in Lithuania in the context of global environmental changes

Investigations have been carried out in order to reconstruct the palaeoenvironmental changes during the earliest Pleistocene interglacials and to establish their relation to global environmental changes. Three sections in east Lithuania exposing the earliest Pleistocene lacustrine deposits lying between the Kalviai (Glacial B, Nidanian?) and Dzūkija (Sanian 1) and between Dzūkija (Sanian 1) and Dainava (Sanian 2) glacial deposits were selected for study. Until now the Šlavė-2 and Vindžiūnai-136 successions were considered to have formed during the Vindžiūnai (Augustovian?, Malopolanian) Interglacial and the Kudrė-915 succession during the Turgeliai (Cromerian IV, Ferdynandovian) Interglacial. Geochemical, palaeomagnetic, magnetic susceptibility, anisotropy of magnetic susceptibility and palaeobotanical proxies were applied to establish the cyclicity and dynamics of palaeoenvironmental change. The data obtained enable the subdivision of the section into units related to changes in the sedimentary environment. The Matuyama/Brunhes boundary and Jaramillo subchron of the Matuyama chron have been recognized in the Šlavė section. The results enable correction of the stratigraphic position of the sections studied. The sedimentation in the Šlavė section took place during the Early Pleistocene, while that at the Vindžiūnai-136 and Kudrė-915 took place during two different Middle Pleistocene interglacials