Cover of the Last Glaciation Deposits in the Eastern Barents Sea: Specificity of Composition, Thickness Distribution, Immensity, and Peculiarity of Structural Forms

Resumo

Analysis of the data of seismoacoustic investigations and geotechnical drilling in the Eastern Barents Sea has shown the following. The cover of the Upper Weichselian glacial deposits spreads regionally. It represents a seismostratigraphic complex (SSC) SSC III, which occurs unconformably on the Mesozoic deposits and partly on the Lower Weichselian morain (SSC V) and is overlain unconformably by the Late Glacial glaciomarine (SSC II)–Holocene marine (SSC I) sediments. SSC III consists of two seismofacies (SF). The dominant SF III-C is represented almost entirely by ordinary moraine, and SF III-T is represented by M-moraine. The occurrence of these moraines almost totally determines the distribution of the SSC III thicknesses. The ordinary moraine thickness varies from <10 m to 10–25 m. The M-moraine forms positive accumulation bodies huge in plan with a thickness of >25 m, reaching 50–75 m. The Upper Weichselian deposit cover has also exhibited other immense structural morphological elements: end moraines (a giant form has been recorded) and powerful subglacial cuts representing a unique unburied analog of so-called tunnel valleys. The features of the structure, composition, and thicknesses of the SSC III deposit cover are determined by the specific character of the development of Last Glaciation in the region.