Facies system of the Eastern Barents Sea since the last glaciation to present

Twenty-two sediment cores raised from the central and eastern parts of the Barents Sea have been studied to reconstruct the evolution of the facies system since the Late Weichselian glaciation. Multiproxy records reveal four lithostratigraphic units, which reflect major development stages of paleoenvironments. Age control is provided by 23 AMS ¹⁴C dates for Holocene sections of four cores. Continental moraine deposits of the last glaciation are overlain by proximal glaciomarine facies of the initial deglaciation phase. During this phase, the Barents Sea ice sheet detached from the ground resulting in seawater penetration into troughs, iceberg calving, deposition of IRD and fine-grained glacier meltwater load in newly formed marine basins. The main deglaciation phase is characterized by pulsed sedimentation from various gravity flows resulting in accumulation of distal glaciomarine facies comprising laminated clay and sand sequences with minor IRD. Redistribution of fine-grained suspended matter by bottom currents and brine-induced nepheloid flows combined with biogenic processes and minor ice rafting caused facies diversity of the Holocene marine sediments. The Holocene facies of shelf depressions reflect rather high, but variable productivity responding to climate changes and variations of Atlantic water inflow into the Barents Sea.     

Facies Variability of Surface Sediments from the Ob-Yenisei Shoal and the Ob and Yenisei Estuaries

Recent sedimentary environments and facies of the southern Kara Sea are described. Lithological, mineralogical, geochemical, and micropaleontological indicators are used to characterize the facies variability. Some mechanisms of mineralogical and geochemical differentiation, which contribute to the facies zonation, are revealed.     

History of Holocene Sedimentation in the Southern Kara Sea

Two bottom sediment cores (BP00-23/7 and BP00-7/6) recovered from the Yenisei transect in the southern Kara Sea are described. Data on their grain size composition, clay and heavy mineral assemblages, and distribution of a large group of chemical elements are presented. Radiocarbon dates based on AMS C-14 method suggest the Holocene age of sediments in the cores. Literature data on physical properties and foraminifers have also been analyzed. The facies affiliation of the lithostratigraphic subdivisions has been unraveled. History of the Yenisei River runoff in the Holocene has been reconstructed on the basis of different indicators.     

History of Sedimentation on the Voring Plateau (Norwegian Sea) during the Last 25 ka

Based on sedimentological, mineralogical, geochemical, and micropaleontological data on the comprehensively investigated Core ASV 1372, the late Pleistocene-Holocene sedimentation history is reconstructed for the Voring marginal plateau (continental margin of the Norwegian Sea). The age model is constructed based on the correlation with several adjacent cores, for which the AMS radiocarbon dates are available. Lithostratigraphic correlation made it possible to compare stratigraphic division of Core ASV 1372 with other cores recovered from the Voring Plateau and the shelf and continental slope off the central Norway. It is concluded that the compositional and structural features of sediments are correlated with paleoclimatic and paleoceanographic changes, variations in provenances, as well as agents and pathways of sedimentary material transport.