ИСТИНА

Tidal marsh deposits are important place for carbon stock and also natural archives that are able to provide evidences on landscape dynamics, sea level and climate changes in the past (Engelhart and Horton 2012; Shennan 1989; Vink et al. 2007). We studied the composition of deposits of the marshes in two Arctic sites, the Kuznetsk Bay of the Pechora Sea and the Baydaratskaya Bay of the Kara Sea. Peat deposits at the Kuznetsk Bay had low overall thickness. Moreover, organic interlayers were detected in the bottom sediments of the bay at a depth of 4 m below the modern level. This indicates that the sea level in the region was rising continuously during the Holocene. Thus, the absence of highstand in the mid-to-late Holocene indirectly confirms the presence of a sinking glacioisostatical forebulge, leading to a faster rise in the Pechora Sea level compared to the world average. At the western coastal ledge of the Baydaratskaya Bay the peat deposits with a total thickness of 114 cm were extracted. Radiocarbon dating showed peat formation during 150 years (from 6857±35 to 7109±35 BP). This indicates favorable conditions for vegetation growth and peat accumulation during the period of the stable Arctic Ocean level. The data obtained contribute to understanding the paleogeographic conditions of the Holocene in the Arctic. Detailed analysis of other proxies will bring additional data for reconstruction of paleoclimate and landscape dynamics in the Arctic coastal area.