The Paleogene Motion of Greenland Relative to North America: Plate Reconstructions of the Davis Strait and Nares Strait Regions

James Chalmers

A simplified plate kinematic model for the Paleogene motion of Greenland relative to North America has been developed that provides a new framework for modeling the oceanic spreading system in Baffin Bay and the intra-plate tectonic development of the Davis Strait and Nares Strait regions of the Arctic. Spreading centers and fracture zones interpreted from satellite derived gravity data in Baffin Bay have been combined with fracture zones in Labrador Sea from published sources to calculate single Euler rotation pole for the C13N to C24N Eocene motion of the Greenland Plate relative to North America. 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 magnetic profiles in central Baffin Bay to identify a C24R Paleocene spreading center and C25N-C26N-C27N magnetic lineations. Previously unpublished aeromagnetic data over northeastern Baffin Bay have been used to identify a new fracture zone in northern Baffin Bay. The proposed limits of Eocene and Paleocene oceanic crust are consistent with interpretations of wide-angle refraction seismic data published by other researchers. 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, also confirmed by refraction data, that was subsequently inverted by approximately 300 km of transpression along the Ungava Fault/Fracture Zone during the Eocene. Subaereal volcanics, extending from Saglek Basin to Melville Bay, are shown to have formed in two distinct zones of eruption. 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.

AAPG Search and Discovery Article #90177©3P Arctic, Polar Petroleum Potential Conference & Exhibition, Stavanger, Norway, October 15-18, 2013