Geophysical observations and a radical model for the the North Atlantic and Iceland

Analysis of teleseismic data from a seismological experiment in the East Greenland Caledonides revealed an east-dipping sub-crustal high velocity structure. The geophysical model indicates the presence of eclogite in the dipping layer beneath a hydrated/serpentinised mantle wedge. The structure is therefore interpreted as a fossil subduction and may have radical implications for our understanding of the North Atlantic. 
Comparison with the very similar and well-known “Flannan reflector” in northern Scotland suggests that these two structures were once connected and now separated by the North Atlantic Ocean. Spatial correlation with geodynamic events and structural peculiarities in the North Atlantic suggests a major control of such a structure on the plate tectonic evolution. For example, the Greenland-Faroe-Iceland Ridge formed where the North Atlantic rift crossed the proposed structure. The Jan Mayen Microplate has separated to the north of this intersection.
Numerical modelling shows that rifting across such a fossil subduction zone complex can explain important features of passive margins and their formation, such as the magmatic budget, asymmetry and “high velocity lower crustal bodies”. On larger scale, delamination of dense orogenic crustal root and lithosphere is presented as a model for the formation of lower mantle upwelling and the formation of Large Igneous Provinces. Crustal flow might explain part of the anomalous thickness of the Greenland-Iceland-Faroes Ridge.