A new model for the Paleogene motion of Greenland relative to North America: Plate reconstructions of the Davis Strait and Nares Strait regions between Canada and Greenland

Abstract

A simplified plate kinematic model for the Paleogene motion of Greenland relative to North America has been developed to provide a new framework for modeling the oceanic spreading system in Baffin Bay and the intraplate tectonic development of the Davis Strait and Nares Strait regions of the Arctic. A single Euler rotation pole was calculated for the C13N to C24N Eocene motion of the Greenland Plate relative to North America using spreading centers and fracture zones interpreted from satellite derived gravity data in Baffin Bay combined with fracture zones in Labrador Sea from published sources. A single stage pole is proposed for the C25N to C27N portion of the Paleocene and a short‐lived stage pole was found necessary to accommodate the C24N to C25N interval. This kinematic model has been used to reinterpret published shipborne magnetic profiles in central Baffin Bay to reveal a Paleocene spreading center and limits of both Eocene and Paleocene oceanic crust. Aeromagnetic data over northeastern Baffin Bay have been used to identify a new fracture zone in northern Baffin Bay. Plate reconstructions are presented incorporating constraints on plate boundaries from onshore and offshore geological and geophysical mapping. Within the Davis Strait, Paleocene oceanic crust was emplaced in an elongated rift that was subsequently inverted by approximately 300 km of Eocene transpression along the Ungava Fault Zone. In the Nares Strait Region, a “microplate” scenario is presented to explain the simultaneous formation of the Lancaster Sound Rift Basin and complex deformation within the Eurekan Orogenic Belt.

Tectonic variation and structural evolution of the West Greenland continental margin

“…The onset of the second rifting event took place in the early Tertiary (Chron 27, c. 61 Ma) and was probably associated with seafloor spreading along the West Greenland margin (Oakey and Chalmers, 2012). Extrusion of plateau basalts in both offshore and onshore West Greenland took place in the late Palaeocene and Eocene and is overlain by the fluvio-deltaic and marine sediments of early Palaeogene age (Chalmers, 2012).…”

“…The Precambrian bedrock of the West Greenland area consists of Achaean and Proterozoic crystalline rocks characterized by numerous complex terranes and suture zones (Hoffman, 1988;Oakey and Chalmers, 2012).…”

“…For example, until recently the opening of Labrador Sea was considered to be of Late Cretaceous age Srivastava, 1989, Oakey, 2008). New evidence, however, using wide-angle seismic velocity analysis, gravity, magnetic and single Euler rotation pole models, proposed the onset of seafloor spreading to be Palaeocene in age, justifying Eocene motion of the Greenland Plate relative to North America (Chian and Louden, 1994;Chalmers and Laursen, 1995;Oakey and Chalmers, 2012). In addition, the West Greenland margin is categorized as non-volcanic on it Southwest section and volcanic to the North (Keen et al, 2012).…”

“…Other issues related to the geodynamic evolution of the Western Greenland margin include the presence of 20 km thick igneous crust underlain by 4 km thick layer of unknown affinity and the tectonic significance of the Ungava transform fault zone (Funck et al, 2007;Funck et al, 2012). On the northern Baffin Bay, the transition zone to oceanic crust is characterised by a high gravity anomaly and magnetic anomalies dated as Eocene at N27-25N and 24N-13N (Whittaker et al, 1997;Oakey and Chalmers, 2012).…”

“…The evolution of West Greenland during continental breakup is controversial. Diverse opinions centre on the timing of uplift, on the number of phases of extrusive volcanism, on the initiation of rifting, sea-floor spreading and geotectonic development of the region during the continental breakup (Korstgärd and Nielsen, 1989;Storey et al, 1998;Larsen et al, 2009;Funck et al, 2012;Oakey and Chalmers 2012;Suckro et al, 2013).…”