Loess-paleosol sequence at Korshiv (Ukraine): Chronology based on complementary and parallel dating (TL, OSL), and litho-pedosedimentary analyses

摘要

The paper concerns the issues of age as well as lithological and pedological development of the loess-paleosol sequence available for direct research at the Korshiv site in the Volhynian Upland (West Ukraine). For dozens of identical samples, a series of comparative laboratory TL dating (Gdansk, Lublin) and OSL dating (Gliwice) was performed, supplemented by the physicochemical and micromorphological analyses. Due to the different dating techniques used in individual laboratories, the details of their methodology were also presented. The resulting series of dates confirmed the lithological and pedos-tratigraphic diagnosis of the sediments during the last two loess-forming cycles. Additionally, the age of the loess layer at the base of the available sequence was established. It was defined as loess L5 and correlated with MIS 12. The resulting age of the mineral substrate in different laboratories shows considerable similarity (upper sequence), but also clear differences (lower part). The OSL dates were younger than the TL dates. Two high-rank fossil soil complexes investigated in the profile represent MIS 7 and 5. For the Eemian-Early Weichselian pedocomplex (S1), the tripartite structure of the younger paleosol represents Early Weichselian Glaciation (MIS 5.4-5.1). The dates helped to conclude that there is a possibility of stratigraphic separateness of the Dubno soil (MIS 3). The whole youngest sedimentary sequence is dated from 20 to 14 ka and correlates well with the period when the Last Glacial ice sheet advanced during its main stadial in Poland.