A differentiated palynological record of the Eemian interglacial in two palaeolakes Niesadna and Parysów from the Garwolin Plain (Central Poland)

Abstract

Two neighbouring Eemian (MIS 5e) palaeolakes, discovered during works on reambulation of the Garwolin sheet of the Detailed Geological Map of Poland (scale 1: 50 000), revealed differences in the palynological record of the succession of the Eemian interglacial. In the profile of Parysów WH-125, a very pronounced hiatus in the transition from the mesocratic to the telocreatic period, i.e. from the hornbeam to the spruce-fir zone, is visible. In the pollen diagram of Niesadna, the maximum percentages reached by Quercus, Corylus and Carpinus are very low, although this is undoubtedly an Eemian succession. The reasons for this should be sought in the presence of several sedimentary gaps probably caused by the different geological and geomorphological conditions of the Niesadna palaeolake located on a slope as opposed to the Parysów palaeolake, which was formed by the melting of a block of dead ice in the process of deglaciation of the area during the late Saalian (MIS 6). An additional rationale for the hypothesis of extremely unfavourable conditions for undisturbed sedimentation in Niesadna palaeolake is its geological-geomorphological situation that caused admixtures of mineral material in the organic sediment, including sand intercalations, indicating that erosion was taking place. The two developed pollen successions were presented against other published data on the Eemian interglacial in the Garwolin Plain, with particular emphasis on the continuity of the Eemian succession. The palynological results showed that the Parysów WH-125 profile joins several other profiles lacking representation of the upper part of the hornbeam zone and sometimes also the lower part of the spruce-fir zone (e.g. Żabieniec, Jagodne). On the other hand, the presence of distinct sedimentary gaps in the oak, hazel, and hornbeam zone, as is the case in the Niesadna profile, has not been recorded in any of the profiles in the Garwolin Plain examined to date. The Eemian pollen succession in the studied Niesadna and Parysów palaeolakes is presented against the broader background of the course of this interglacial in the European Lowlands.