The Svalbard–Kara plates junction: structure and geodynamic history

Abstract

The structure and geodynamic history of the northern Barents–Kara continental margin, which had formed mostly by the latest Paleozoic, have been investigated using offshore geological and geophysical data and geological evidence from adjacent landmasses. In the context of the suggested model, the Saint Anna trough is interpreted as a boundary tectonic element between the Svalbard and Kara plates. Thus, the study focuses on a complex tectonic node with its structure having implications for the trough origin, as well as for the history of geodynamic relations among Arctic cratons and microplates. Trough structures of different ages in the area, including the northeastern East Barents trough and the St. Anna trough, appear to be a zone of triple or T-shaped junction. The reported reconstruction of the trough system history since the Middle Paleozoic shows that the St. Anna trough joined the East-Barents system in the Late Permian–Triassic to become its new segment extending the system to the north.

Structure and evolution of the northern Barents-Kara Sea continental margin from integrated analysis of potential fields, bathymetry and sparse seismic data

“…Gramberg et al (2001a) outlined a sedimentary basin beneath the St. Anna Trough. This basin is inferred to be linked to the Eastern Barents Basin and comprises around 12 km of Palaeozoic and Mesozoic sediments (Shipilov & Vernikovsky 2010;Ivanova et al 2011). The analysis of bathymetry and isostatic equilibrium assumption requires a thick sedimentary cover in front of the St. Anna and Voronin troughs (Fig.…”

“…A regional 3-D geophysical model of the Barents Sea region was created by Ritzmann et al (2007). The sedimentary thickness estimates obtained from seismic reflection profiles found in the works by Johansen et al (1992), Gramberg et al (2004), Jokat & Micksch (2004, Poselov et al (2006), Engen et al (2009) andShipilov &Vernikovsky (2010) were projected onto the constructed profiles where it was possible. A probabilistic seismic model for the Barents Sea region has recently been published by Hauser et al (2011).…”

“…Sakoulina et al (2003), (2007), Ivanova et al (2006Ivanova et al ( ), (2011 and Roslov et al (2009) published the results of ocean bottom seismometer (OBS) surveys, supplemented by coincident MCS data along regional lines across the eastern Barents Sea and Kara Sea (Fig. Shipilov & Vernikovsky (2010) compiled a sedimentary thickness map, accompanied by a series of seismogeological cross-sections for the southern part of the St. Anna Trough (Fig. Shipilov & Vernikovsky (2010) compiled a sedimentary thickness map, accompanied by a series of seismogeological cross-sections for the southern part of the St. Anna Trough (Fig.…”

“…An efficient 3-D gravity inversion method that considers the gravity effect of a thermally differentiated mantle was developed by Chappell & Kusznir (2008b). Transects for modelling are shown by red lines with the transect number; locations of seismic data used are shown by stippled lines and white points: 'a1-a14'-single-channel seismic reflection data compiled during MAST (Map of Arctic Sedimentary Thickness) project (Poselov et al 2006); 'awi2001' and 'c'-MCS data collected by the Alfred Wegener Institute (Geissler & Jokat 2004;Jokat & Micksch 2004); 'prof15'-MCS profile NPD-POLAR-15 (Engen et al 2009); 'b'-refraction observations (Duckworth & Baggeroer 1985); 'd'-coincident MCS and wide-angle observations '1-AR' (Sakoulina et al 2003); 'e'-MCS data (Johansen et al 1992); 'f'-seismic profiles from Shipilov & Vernikovsky (2010); 'g'-coincident MCS and wide-angle observations '3-AR' (Roslov et al 2009); 'h'-coincident MCS and wide-angle observations '4-AR' (Sakoulina et al 2007); 'i'-MCS profile from Baturin et al (1994); 'J' and 'k'-OBS profiles by Czuba et al (2005Czuba et al ( , 2008 and 'L' and 'm'-OBS profiles by Breivik et al (2005) and Minakov et al (2011), respectively. Seismic data coverage at the northern Barents-Kara Sea margin.…”

“…2). Shipilov & Vernikovsky (2010) compiled a sedimentary thickness map, accompanied by a series of seismogeological cross-sections for the southern part of the St. Anna Trough (Fig. 2).…”