This paper presents the results of palaeobotanical studies (pollen and plant macrofossil analyses) of the sediments from the profile Michałowo P-3 (Gródek-Michałowo Depression, NE Poland). At this profile the second bed of peat under Holocene peat and the layer of silts and sands was discovered. The pollen succession indicates that they were deposited, with some gaps, from the beginning of Eernian Interglacial to Early Vistulian. The local pollen zones, distinguished in the pollen diagram, correlate with the regional pollen stratigraphy of the Eemian Interglacial, but the pollen record of hornbeam (ES R PAZ) and spruce (E6 R PAZ) regional zones is absent in Michałowo. In the middle part of the Michałowo pine zone (Mi-5 Pinus L PAZ), a cool oscillation of climate is marked by an opening of forests and development of herb plant communities.

Pollen analysis was performed on 14 profiles of fossil biogenic sediments from different parts of the vast depression near the Wola Starogrodzka village (Central Poland). The results allowed the determination of the time of their accumulation for the period from the end of the Odra Glaciation (Warta Stage, Saalian, MIS-6), through the Eemian Interglacial (MIS-5e), to the first interstadial of the Early Vistulian (Brørup, MIS-5c). In many studied profiles, we noted the incompleteness in the pollen record of the Eemian vegetation succession – hiatuses occur usually in the hornbeam (E5) and/or spruce phase (E6). Moreover, the thickness of the same pollen zone and the development of its palynological record are strongly differentiated between individual profiles, e.g. the hornbeam zone (E5) is contained in an exceptionally thick sediment layer (3.7 m) in the PWS1-19 profile, and the oak zone (E3) in the WH-123 and PWS2-19 profiles (1.0 and 1.2 m, respectively), while in other profiles they are represented only by single pollen spectra. If we only had a single profile with a hiatus and/or a poorly developed pollen record, it would be impossible to reconstruct a complete interglacial succession of vegetation. However, having several such imperfect profiles which complemented each other enabled us to do it.