Precambrian–Palaeozoic geology of Smith Sound, Canada and Greenland: key constraint to palaeogeographic reconstructions of northern Laurentia and the North Atlantic region

Abstract

Nares Strait separating Greenland and northernmost Canada is floored by continental crust. Most palaeogeographic reconstructions of Laurentia and the North Atlantic region model the seaway as the site of massive sinistral strike–slip and/or compression/transpression, subduction and collision, the supposed manifestations of the hypothetical Wegener Fault. However, these reconstructions fail to take into account the bedrock geology that represents within‐plate evolution. Both sides of Smith Sound, the southernmost part of Nares Strait, expose the same early Proterozoic to early Palaeozoic assemblages that are unaffected by seaway‐related tectonism or thermal activity. Smith Sound is an intact crustal block or `linchpin' demonstrating that there was no independent Greenland plate. North‐west Greenland was not a leading plate margin neither was Nares Strait the site of the plate boundary between Greenland and North America. The Wegener Fault does not exist. The Smith Sound linchpin constitutes a key constraint that must be respected in any palaeogeographic reconstruction of the region.

Quantifying Provenance and Transport Pathways of Holocene Sediments From the Northwestern Greenland Margin

“…Other Proterozoic sedimentary rocks are also outcropping in the northwestern part of Greenland and southern part of Ellesmere Island (surrounding Smith Sound) and form the Thule Supergroup (e.g., Dawes, ). At the end of the Cretaceous and early Tertiary, Greenland and North America were separated by the formation of rifts, which disconnected the Precambrian cratons (e.g., Dawes, ; Dawes et al, ; MacLean et al, ). The development of large grabens and basaltic lava flows (Palaeogene) along the Canadian and Greenlandic margins (basaltic and picritic eruptions into a low‐lying coastal environment), in the region of Disko and Ummannaq Bays, was associated to this rifting (Figure b; Escher & Pulvertaft, ; Larsen & Pedersen, ).…”

Chapter 44 Geology and petroleum potential of the Lincoln Sea Basin, offshore North Greenland

“…Eurekan structures in the Canadian Arctic Islands are traditionally interpreted as being caused by movements linking ocean floor spreading in the Arctic Ocean with presumed ocean floor spreading in the Baffin Bay region (Kerr 1982). The role of the Nares Strait in this context remains a matter of debate (Oakey & Damaske 2006;Dawes 2009). …”

Metallogeny of Greenland

“…The Paleozoic sedimentary rocks unconformably overly the Proterozoic sedimentary sequences of the Independence Fjord and the Hagen Fjord groups and the Thule Supergroup(Figs. 11, 29;Higgins et al, 1991;Dawes, 2009;Higgins, 2015).Sedimentation started in the Neoproterozoic and lasted until the Early Devonian, when the basin was inverted during the Ellesmerian Orogeny(Higgins et al, 2000). Rocks of the continental margin of Laurentia are also preserved in the Caledonian Orogen in eastern Greenland, where the sedimentary rocks including flysch are deformed by Middle Silurian thrusts (Fig.…”