Deep seismic investigation across the Barents-Kara region and Novozemelskiy Fold Belt (Arctic Shelf)

Since 1995 SEVMORGEO has collected wide-angle reflection/refraction profiling (WARRP), multichannel seismic data (MCS) and seismoacoustic profiling, along regional lines 1-AR, 2-AR and 3-AR. These lines cross the whole Barents-Kara Region and Novozemelskiy Fold Belt. As a result, new geological data about the deep structure of the Earth's crust have become available. Four main tectono-stratigraphic units are distinguished in the section of the Earth's crust: (1) a sedimentary cover; (2) the Upper Proterozoic (mainly Riphean for the Barents Plate) and Riphean-Paleozoic (the South-Kara Syneclise) deformed and folded complexes; (3) the upper crystalline crust (granite-gneissic metamorphic Archean-Proterozoic complex); (4) the lower crust (basalt complex). The Barents-Kara Region is characterized by moderately thinned continental and subcontinental crust with an average thickness of 37-39 km. On islands and areas of uplifts with ancient massifs, the thickness of the crust (38-42 km) approaches the typical crust for a continental platform. In the Novozemelskiy Fold Belt the thickness of the crust reaches 40-42 km. Rift-related grabens are characterized by significant crustal thinning with thicknesses of 33-36 km. Several grabens are revealed: the Riphean Graben on the Kola-Kanin Monocline, the Lower Paleozoic West-Kola Graben, the Devonian Demidovskiy Aulacogen, the Upper Paleozoic Malyginskiy Graben in the Barents Region and Upper Paleozoic-Triassic Noyabr'skiy and the Chekinskiy grabens in the Kara Region. Data concerning the deep structure lead us to conclude that mainly destructive processes contributed to the dynamics of the forming of the Barents-Kara Region.