Article,
Deep seismic investigation across the Barents-Kara region and Novozemelskiy Fold Belt (Arctic Shelf)
Tectonophysics, 420 (1-2): 123--140 (Jun 26, 2006)
DOI: 10.1016/j.tecto.2006.01.011
Abstract
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.
