Abstract [eng] |
The formation of the database of results of geochronological dating of Pleistocene sediments of Lithuania was one of the main purposes of the master work. The results of 375dating made by different methods of absolute geochronology (14C, 10Be, U-Th, OSL, TL, ESR) from 99 geological objects (boreholes, outcrops, erratic boulders) were collected in the mentioned database. The estimation of validity of stratigraphic schemes of Quaternary of the Lithuania published by different authors or official institutions was done. The model of the development of the paleogeographic conditions in the Lithuania during the Middle and Upper Pleistocene as well as the scheme of the deglaciation of territory of Lithuania during the Last Glaciation are presented. According to the results of geochronological dating, there are possible to distinguish Būtėnai, Snaigupėlė and Medininkai Interglacials as well as Žemaitija, Medininkai and Upper Nemunas Glaciations in the Quaternary stratigraphy scheme of Lithuania. The most intensive melting of the ice sheet of the Last Glaciation started about 18 kyrs BP, whereas the complete deglaciation of the entire territory of Lithuania occurred about 13-14 kyrs BP. The final melting of separate blocks of the died ice could be finished about 10 kyrs BP. There is possible to distinguish only one readvance (oscillation) of the ice sheet during the Last Glaciation; there aren’t any backgrounds for separation stadials – interstadials of phasials – interphasials. |