3D Lithospheric Model of the NE Atlantic Margin

Claudia Haase

We present a well-constrained 3D model for the North-East Atlantic margin lithosphere. The 3D model is based on a wealth of seismic profiles, commercial and scientific borehole data from the shelf and mainland NO, petrophysical sampling and a dense coverage of gravity and aeromagnetic data. The model is based on interpretation of satellite gravity gradient data and gravity compilations of the area, which complement each other with respect to their depth sensitivity. The 3D model provides a detailed picture from the upper mantle to the top basement (base of sediments). The latter horizon is well resolved from gravity and especially magnetic data. Sedimentary layers are constrained from seismic studies, but do in general not show a prominent effect in the gravity and magnetic field. In the North Atlantic, both gravity field and geoid and are strongly affected by a regional component, which reflects the presence of density changes associated with the Iceland plume and the thermal structure of the upper mantle. The gravity gradient data are less affected by this regional trend, which makes them a useful addition to optimize model parameters, and it can be shown that they can be used to study the upper mantle. The model provides the geophysical constraints to study the dynamic processes and tectonic evolution of the NE Atlantic, and to test concepts of margin evolution and links between the onshore and offshore domain.