OSL dating of Middle Weichselian age shallow basin sediments in Western Latvia, Eastern Baltic

This paper presents the results of the first attempt to date the Quaternary sediments of western Latvia in the southeast Baltic region, using luminescence. The analyses have been carried out on sandy sediments of the Jurkalne Formation that are located between upper and lower Scandinavian sourced tills. Previous publications on the origin of the Quaternary sediments in the region are reviewed and it is found that there are a wide range of explanations for their processes of formation and their age of formation. It is concluded that although the sandy sediments were deposited in freshwater environment although they contain both marine and freshwater fauna and flora, a property that is explained by derivation and glaciotectonic deformation and mixing.The samples used for dating were collected from surface exposures and boreholes and yield results that range in age from 52 ± 10 ka BP to 26 ± 4.1 ka BP. As a result of this study it is suggested that the dated sediments were deposited in a freshwater basin during MIS 3 and are overlain by a till deposited by Scandinavian Ice during the Late Weichselian (MIS 2/LGM). The underlying till is attributed to a Middle Weichselian glaciation and tentative suggestions are presented for the age of other deposits that underlie the dated sediment.