Evolution of the Voring volcanic margin

Abstract

The Voring Margin experienced crustal uplift and extension prior to breakup, restricted to a Tertiary marginal basin west of the present shelf edge. Initial volcanic surge and shallow extrusion level are related to a higher than normal temperature at the base of the lithosphere, inducing partial melting combined with opening in previously thinned crust. The commonly described non-extensional nature of this margin is only an apparent phenomenon. Except for the outer basin, extension by dike injection coupled with high strength of the thin, pre-opening crust in the Voring Basin precluded the formation of a faulted rift unconformity. We believe these observations have relevance for volcanic margins elsewhere, but infer that seaward-dipping reflectors can form in many environments. The Voring Plateau marginal high and other similar features in the North Atlantic are an integrated part of the North Atlantic Volcanic Province, which extends 2000 km longitudinally. Compared to the central, transverse, part of the province in the vicinity of the Iceland hotspot that has been active for 60 m.y., marginal volcanism was transient, related to breakup and lasting only for a maximum of about 3 m.y. -from Authors