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The Barents Sea area is the effect of a complex process that involved different orogenic and rifting phases. The resulted lithospheric structure and the tectonic setting are still not completely understood. To find answers at the major issues we performed geophysical study in the area and develope a new 3D model which provides new insight into the regional lithospheric setting and evolution of the Barents Sea.
We apply 3D forward modelling techniques using IGMAS software package that allows as to interpret gravity, magnetic and geoid fields at the same time. An initial model has been defined using the existent seismic velocity models (BARENTS3D with 50 x 50 km resolution), the petrophysical databases and the available structural maps.
Since the geoid undulations are inverse proportional at the distance of the source we used it to investigate the deep density contrast: Moho geometry and upper mantle density variation. Differently the gravity anomalies depend of the inverse of the square of the source distance; that means that are more sensitive to the shallower anomalies and we are able to explain the Moho and the basement density geometry. Considering the magnetic property of the different rocks the anomaly effect of the sedimentary layers can be neglect, instead the effect of the magnetic basement can be interpreted to refine its geometry, its susceptibility distribution and to delineated different domain.
The result is a model that defines the lithospheric structure and the geophysical parameters for the Barents Sea on a regional scale. The accuracy, uncertainties and limitation of our model in respect to the available database will also be discussed.
The model has many implication and give as an important contribution to a better understanding of the area. The geometry of the final model refines the lithospheric setting of the area, the different basins geometries between the Eastern and the Western Barents Sea are clearly delineated, especially the extraordinary mega-scale basins in the Eastern Barents Sea. The link between the upper mantle density structures and the Eastern Barents Sea Basin is certainly a key to unveil the formation of the mega-basins with up to 20 km of sedimentary succession. The densities parameters are justified in consideration of petrophysical models and gives petrological implication that help to understood the geodynamic of the region.
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