Genesis of the lithosphere of the Iceland region (North Atlantic) according to geophysical data

Abstract

The geothermal and geomagnetic data on the Iceland region are mapped. On the basis of the analysis of geological, tectonic, geothermal, and geomagnetic data and on the information on the age and character of the volcanism at the European and Greenland rifting margins, the principal evolution stages of the Iceland region are substantiated. The modeling estimation of the rates of thermal subsidence of the Reykjanes and Kolbeinsey ridges and of the Greenland-Iceland and Iceland-Faeroes sills shows their more than 20% difference. The different rates of thermal subsidence of the structures are caused by various effects of hot matter of the mantle plume, its volume, and the different genesis of the lithosphere. The formation of the lithosphere of Iceland Island, besides the plate and plume tectonics, involved the thermophysical processes of the transformation of the lithosphere of continental genesis. This is confirmed by the analysis of the spreading rates, basalt age, and the data of the geochemical and isotope studies of volcanic rocks. The numerical modeling performed points to the presence of an additional heat source related to the plume hot matter in the Iceland region (Iceland Island, 30 mW/m2; the Reykjanes and Kolbeinsey ridges, 15 mW/m2), which conforms to the data of magnetotelluric geochemical studies.