The E Greenland continental margin: a trasition between oceanic and continental magmatism

The E Greenland continental margin differs from typical margins in having a superimposed regional uplift which has exposed the early rift products for direct examination. Most of the igneous rocks in this region find counterparts in the oceanic setting with the proviso that the area is part of an aseismic ridge. Thus, picrites, basalts, sheeted dyke swarms and layered gabbros are present and these can be used to shed light on oceanic magmatic events. Nephelinitic rocks are products of off-axis volcanism and find no counterparts in the present oceanic rift system, although they occur in marginal regions of the ocean basins and were generated in distal regions at the initiation of rifting in Icelandic anomaly. Voluminous salic rocks in the area owe their generation largely to continental crust which has undergone extensive melting. They find no direct counterparts in oceanic areas. The outstanding degree of exposure in this area combined with its transitional nature and wide spectrum of rock types make it a unique laboratory for the elucidation of a variety of problems regarding both oceanic and continental volcanism together with the nature of rifted continental margins in general.