Diatom stratigraphy of the Mazovian Interglacial lacustrine sediments in southeastern Poland

The sediments of fossil lakes at Adamówka, Krępiec and Biała Podlaska are here the object of biostratigraphic comparison and correlation on the basis of diatom analysis. These sediments fill various lakes that have developed during, or shortly after the Sanian 2 Glaciation. Adamówka and Biała Podlaska represent small, shallow, melt-out lakes, whereas Krępiec represents a larger, deeper lake created in a postglacial valley of tectonic origin. Four Local Diatom Assemblage Zones were determined at Adamówka and Krępiec and five zones in Biała Podlaska. These local zones correspond to the three and four pollen periods, respectively, of the Mazovian Interglacial. The Adamówka site is characterized mainly by the Cyclotella-Fragilaria flora, the Biała Podlaska site by Fragilaria-Cyclotella-Aulacoseira and Krępiec by Stephanodiscus-Cyclotella-Aulacoseira-Fragilaria. The identified diatom succession and the presence of characteristic diatoms (Cyclotella comta/or C. radiosa var. lichvinensis and var. pliocaenica, C. cf. temperiana and C. vorticosa/or C. schumannii) evidence the same age - Mazovian (=Holsteinian, Likhvinian, Alexandrian) Interglacial, in accord with the palynological data.