Structure, formation and geochronology of the late Pleistocene and Holocene cover deposits in South-Eastern Lithuania

article The available data of earlier investigations (Basalykas, 1965; Basalykas et al., 1976a,b; Kudaba, 1983) show that deposits of various origin and age are widespread in Asmena Upland and Lyda Plateau (South-Eastern Lithuania). They overlie a polygenetic dislodged marginal formations of the penultimate Medininkai (Warthe) glaciation. Pleistocene deposits in this area are often deformed by solifluction and fluvial erosion and penetrated by cryogenic ice-wedge pseudomorphs. Granulometric, geochemical and petrographic investiga- tions of the deposits have demonstrated that they are characterized by different sources of sedimentary material supply as well as different degrees of physical and chemical weathering. The alternate deposits preserved in the study area imply palaeoenvironmental changes associated with the different palaeoclimatic events. The Ca/Zr ratios in cover deposits testify that the upper beds usually experienced stronger chemical weathering that is associated with warmer climate. The cases of weaker weathering can be explained by