Wide angle converted shear wave analysis of a North Atlantic volcanic rifted continental margin: Constraint on sub-basalt lithology

Abstract

Introduction Continental break-up between Greenland and Europe in the early Tertiary was accompanied by the eruption of > 1 million km3 of basalt flows generated by decompression melting of the underlying, abnormally hot mantle of the proto-Iceland plume (White and McKenzie, 1989). Extrusion occurred extremely rapidly in two phases, an early pre-breakup phase between 62-58 Ma and a main syn-breakup phase from 56 to ~54 Ma (Saunders et al., 1997) with a high rate of magmatism continuing to the present time in Iceland. Lava produced during continental break-up flowed up to 150 km away from the rift across sedimentary basins while intrusion into the lower crust of large volumes of melt caused permanent crustal thickening and uplift across the continent-ocean transition (White et al., 1987). ...