Late Glacial and Holocene paleoenvironments in northwestern Russia as inferred from multi-proxy studies of the sediment sequence from two lakes on Valdai Highlands

Regional features of climate and environmental processes in the Late Glacial time and Holocene have gained quite an attention in the literature. Despite a significant progress achieved in recent years in the region of northwestern Russia, spatial and temporal climatic and environmental features still remain poorly understood. This is due, on the one hand, to the instability and dynamics of climate and environments in the Late Glacial and early Holocene time, to dischronous paleoenvironmental events, and, on the other hand, to the extremely limited number of studied sites with reliable age control.

In this work, we present a reconstruction of environmental and climate evolution since the Late Glacial time, based on the results of ground-penetrating radar profiling (GPR), lithological facies analysis, the analysis of total organic carbon and nitrogen content, spore-pollen and diatom analyses, and also sediments radiocarbon dating of lakes Zvan and Piros located within the Valdai Highlands.

The multi-proxy studies of the sediment sequence from those lakes offers a means of reconstructing Late Glacial and Holocene environmental history.

After the Ice Sheet retreated from the area (≥16 cal. ka BP), most of dead ice mass had degraded ~ 14 cal. ka BP. Karst processes played an important role in the formation of modern lake basins. The modern lake systems established on Valdai Highlands since ~ 10 cal. ka BP. For the first time in this region, the appearance of spruce in the landscape has been clearly dated and referred to the period 14-13 cal. ka BP. Water level and trophic status of small lakes on Valdai Highlands were strongly controlled by climate during the Holocene. Agricultural activity was already widespread in the region ~ 2 cal. ka BP.

This work was supported by St. Petersburg State University grant Id: 38177967