Main Features of the Structure, Lithological Composition, and Thickness of the Quaternary Deposits Cover in the Eastern Barents Sea

Resumo

Analysis of the data of seismoacoustic investigations and engineering-geological drilling in the eastern Barents Sea has shown the following. The Quaternary sedimentary cover of the region with a sharp angular unconformity overlying the pre-Cenozoic strata consists primarily of five seismostratigraphic units (SUs). Lower three of them are represented by moraines: Upper Saalian (SU VII), Lower Weichselian (SU V), and Upper Weichselian (SU III) that includes seismic facies (SFs), SF III-T and SF III-C. The Late Glacial SU II and Holocene SU I, forming the top of the Quaternary section, are composed of glaciomarine and marine sediments, respectively. The SU VII and SU V moraines with eroded upper and lower boundaries (the result of glacial erosion) are partly preserved. The deposits of SUs III, II, and I belong to the last glaciosedimentation cycle, are regionally spread, and have their own features of area development. The sediment thicknesses in all SUs vary from <1–3 to 25–30 m and greater. A heterogenous spatially variable structure of the Quaternary cover in the eastern Barents Sea, manifested in the complex behavior of its thicknesses (from <25 m to 75–100 m), is associated with the processes of the geological development of the region as a part of the Barents Sea glaciated shelf.