The role of climate and eustatic sea-level changes in post-Eemian sedimentary succession in the southern Baltic Sea region

Multiproxy analyses were employed to determine the age and origin of the Pleistocene sedimentary succession at the Kadyny site in the northern part of the Elbląg Heights, northern Poland. Lithofacies analysis yielded the identification of four distinct lithofacies complexes (U1-U4). The units of analysis are fluvial (U1, U3 and U4) and lacustrine-lagoonal sedimentary environments (U2). The formation of the site commenced with the Early Vistulian (units U1, U2 and lower part of U3) and the Lower and Middle Pleniglacial (upper part of unit U3 and unit U4). The sequence of depositional environments was controlled by transgressive-regressive cycles functioning in a glacial-interglacial (main cycle) and stadial-interstadial (secondary cycle) rhythm. The textural characteristics of the sediments and the evolution of vegetation were influenced by climatic factors. The warmest climatic conditions prevailed during the deposition of unit U2 (Odderade Interstadial), which was deposited as a result of fluctuations in the water level in a coastal lake or lagoon separated from the open sea by a sandy spit. The analysed sediments are part of thrust-bounded ridges that form the Elbląg Glacitectonic Complex. These were subsequently thrust-stacked and imbricated, which occurred during the Marine Isotope Stage (MIS) 2 period. This process occurred in two distinct phases: initially from the west, and subsequently from the north. The displacement of the deformed sediments is believed to have taken place over a distance of 10–30 km from the area that is now occupied by the Gulf of Gdańsk.