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Abstract:
The present-day state of the NE Atlantic lithosphere is the product of a complex geodynamic history that includes the continental breakup between Greenland and Eurasia about 55 million years ago, after multiple phases of extensional deformation and the emplacement of the Iceland plume. Open questions related to the process of continental breakup in this area are which role the Iceland plume played and whether we can image the traces of it in the present-day configuration of the crust and mantle. With the present work we aim to contribute to these questions by means of the integration of available geoscientific observations - including seismic profiles, existing geological maps and models, seismic mantle tomography and, particularly, gravity data - into one consistent three-dimensional model. The final model resolves the main structural characteristics, as well as the density distribution, of the crust and upper mantle of the entire NE Atlantic including its conjugate margins of Greenland and Norway. It allows us to correlate the obtained density anomalies in the crust with proposed surface indicators of the plate’s journey over the plume. Besides, mantle density anomalies can be related with the present-day plume location and its interaction with the mid-ocean ridges. The model also indicates major differences in the density configuration between both conjugated margins increasing with the distance to the plume and towards the sheared margin segment. Altogether, our results indicate that the breakup of the continent, with its pre-existing crustal configuration, could have been facilitated by the presence of the plume.
