ESR ages of three lithuanian mid-late pleistocene interglacials methodical and stratigraphical approach

The electron spin resonance (ESR) dating was used for freshwater mollusc fossils taken from interglacial deposits at the Gailiunai and Neravai sites (Butenai/Holsteinian In-terglacial), Valakampiai site (Snaigupele/Drente-Warthe Interglacial), Jonionys and Netiesos sites (Merkine/Eemian Interglacial) in Lithuania. Freshwater mollusc samples from the Butenai/Holsteinian and Merkine/Eemian Interglacials estimated by ESR yielded different ages: Butenai O 455.0 to 307.0 ka and Merkine O 112.5 to 101.5 ka BP. Two ESR dates determined for Snaigupëlë Interglacial deposits suggest an average age of about 113.0 ka. This is therefore younger than expected from the palynological data, and it places Snaigupëlë into the interglacial stage, possibly assigned to the MIS 5d that can likely be correlated with the Merkine/Eemian Interglacial (s.l.). Thus, further studies of the deposits and additional ESR dates are needed to make sure that the Snaigupele bed is really much younger than expected (about 200 ka) in all recognized sites in different parts of Lithuania.