Svalbard: a fragment of the Laurentian margin

Abstract

Abstract The last decade of structural and isotope-age dating studies in Svalbard and East Greenland has provided strong support for the close correlation of these segments of the Caledonide Orogen, as had previously been inferred from stratigraphic evidence. Prior to Tertiary opening of the Norweigan-Greenland Sea, Svalbard’s Caledonian terranes were an essential part of the Laurentian margin, as witnessed not only by the Early Palaeozoic depositional environments and fauna, but also by the character of the Palaeoproterozoic basement, the Meso- to Neoproterozoic cover, the evidence of late Grenvillian tectono-thermal activity, Caledonian structural style and timing of movements, Caledonian granitic magmatism and Old Red Sandstone (ORS) deposition. Recently published maps of East Greenland show the hinterland allochthons of central East Greenland to strike out obliquely into the continental shelf. The hypothesis promoted here requires that they continue offshore northwards, extending to the northern edge of the NE Greenland shelf and that most of the Svalbard terranes were northerly continuations of the East Greenland Caledonides. Only along the west coast of central Spitsbergen are ‘foreign’ terranes exposed that have affinity with Pearya, having been located north of the North Greenland foldbelt, apparently unrelated to Laurentia, prior to Ellesmerian Orogeny. The unambiguous affinity of the Svalbardian and Greenlandian (Laurentian) Caledonides contrasts markedly with the Timanide evolution of northeastern Baltica. It confirms previous interpretations that an important Caledonian suture-zone transgresses northeast-wards across the Barents Sea, separating Laurentian domains in the NW from the Timanides of Baltica in the SE. The Timanides of northeastern Europe are truncated by, and terminate in the Barentsian Caledonides of the Barents Shelf.