Northerns Barents Sea evolution linked to the Arctic Ocean.

Minakov, A., Mjelde, R., Faleide, J. I., Huismans, R. S., Dannowski, Anke , Flueh, Ernst R., Glebovsky, V., Keers, H. and Podladchikov, Y. Y. (2010) Northerns Barents Sea evolution linked to the Arctic Ocean. [Poster] In: AGU Fall Meeting 2010. , 13.-17.12.2010, San Franciso, USA .

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Abstract

The current effort represents a systematic regional study of the vast and poorly sampled area, linking the Barents Sea and the Arctic Ocean. The deep structure of the Northern Barents Sea was examined by means of integration various geophysical techniques, including numerical geodynamic modeling. Ocean Bottom Seismometers data have been acquired east of Svalbard and processed using a seismic refraction/reflection tomography method. A series of crustal-scale geotransects, illustrating the architecture of the Cenozoic Northern Barents Sea margin were constructed using gravity modeling, sparse seismic reflection profiles and depth to magnetic sources estimates. The structure of the Mesozoic passive margin, facing to the Amerasia Basin, was inferred based on a similar technique, involving plate reconstructions. Numerical simulations of the lithosphere extension, leading to formation of the Eurasia Basin, was performed using the finite element method. The velocity structure east of Svalbard exhibits evidences of Cretaceous magmatism. In particular, funnel-shaped high-velocity anomalies, reaching 10% relative to the 1D background model, are interpreted as Early Cretaceous magmatic intrusions. Further to the north, a narrow and steep continent-ocean transition was observed. The conjugate northern (and eastern) Barents Sea - Lomonosov Ridge margins are symmetric and narrow whereas the continent-ocean transition on the Podvodnikov Basin's side of the Lomonosov Ridge is broad. On the continental side, the Northern Barents Sea margin is underlain by Paleozoic-Early Mesozoic deep sedimentary basins separated from the oceanic side by the marginal basement uplift. The Northern Barents Sea, including Svalbard, was not affected by the major Late Jurassic - Early Cretaceous rifting which gave rise to deep basins in the South Western Barents Sea. However, the area experienced widespread Early Cretaceous magmatism. The emplacement of mafic magmas was controlled by Paleozoic rift structures which were reactivated in the Early Cretaceous. The magmatism east of Svalbard developed without significant crustal thinning, but was probably triggered by localized lithospheric weakness zones. The Mesozoic passive margin, originated due to the opening of the Podvodnikov Basin, was subjected to significant crustal thinning. The Northern Barents Sea region together with the Lomonosov Ridge was standing high during most of the Late Cretaceous. The regional uplift sourced from the Alpha Ridge area. The Eurasia Basin's breakup in the Paleocene preceded the opening of the Norwegian Sea, implying a connection to the Labrador Sea. A short-lived lithosphere-scale shear zone has likely facilitated to the detachment of the Lomonosov Ridge microcontinent and onset of seafloor spreading. Shear heating in the mantle lithosphere accompanied the development of the proposed shear zone and served as a mechanism for strain localization.

Document Type: Conference or Workshop Item (Poster)
Keywords: Meeresgeologie
Research affiliation: OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-GDY Marine Geodynamics
Date Deposited: 10 Jan 2011 11:09
Last Modified: 23 Feb 2012 06:05
URI: https://oceanrep.geomar.de/id/eprint/10706

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