New palaeoclimate reconstructions based on multidisciplinary investigation in the Ferdynandów 2011 stratotype site (eastern Poland)

Drilling carried out in 2011 at Ferdynandów (E Poland), serving as a stratotype for the Ferdynandovian Interglacial, enabled its re-examination with high-resolution palynological, plant macroremains, and sedimentological analyses. Lacustrine sediments included a record of the Late Sanian 1 (= Elsterian 1) Glaciation, a complete Ferdynandovian succession, and the Early Sanian 2 (= Elsterian 2) Glaciation. Particular similarities in the succession observed between the Ferdynandów 2011 profile and the adjacent sites of the same age in Łuków-3A and Zdany provide a basis for detailed palaeoclimate interpretation. The Ferdynandovian succession of all the three pollen profiles can be clearly divided into two distinct interglacials separated by a sequence of pollen spectra typical of a glacial succession with pollen zones of stadial-interstadial fluctuations. Warm units in the Ferdynandów 2011 succession correspond to climatostratigraphic units of Ferdynandovian 1 and 2, while the cold unit – to Ferdynandovian 1/2. This division can be applied to all Ferdynandovian successions in Poland and allows their correlation with the early Middle Pleistocene Cromerian Complex of Western Europe (Cromerian II Westerhoven and Cromerian III Rosmalen) as well as with Marine Isotope Stages (MIS) 13–15. For each biostratigraphic unit, mean temperatures of the warmest and coldest months, and mean annual temperature and precipitation were reconstructed. For the comparison with the Ferdynandów 2011 pollen diagram the data based on modern pollen analogues for the Łuków-3A pollen diagram were used