Development of Lake R kyva and its environment in Late Pleistocene and Holocene

Results regarding the development of Lake R kyva (Lithuania) are presented. Radiocarbon dating, pollen and diatom analysis enabled to reveal Late Pleistocene and Holocene conditions in the lake and its environs. Lake R kyva sediments were drilled from the ice surface. Organogenic sediments occur in a 2-m thick layer. The radiocarbon age of sediments determined in four intervals (182-183, 181-182, 128-130, and 78-80 cm) was found to correspond to the Aller d, Late Dryas, Atlantic and the beginning of the Subboreal. Pollen analysis confirmed that sedimentation was going on constantly during the whole Late Pleistocene Holocene. Diatom investigations indicated that water level in the lake was low all that time, with just small fluctuations. Lake R kyva was formed when melt water filled a shallow depression, where bogging began in the Aller d with the climate getting warmer. Western currents and winds drove peat moss remains around the lake and settled them on the bottom.