Regional Crustal Structure Across Baffin Bay, Northern Canada, From Constrained 3-D Gravity Inversion

Welford, J. Kim (Memorial University of Newfoundland) | Dehler, Sonya A. (Natural Resources Canada)

OnePetro 

Baffin Bay, northern Canada, represents the northernmost segment of rifting between Greenland and North America, and can be considered a northern extension of the Labrador Sea extinct rift system between Labrador and Greenland. Many questions remain about the nature of the crust beneath parts of Baffin Bay, although extinct spreading axes and a fracture zone have been previously identified based principally on gravity data. Existing deep seismic coverage over Baffin Bay is spatially limited and mostly concentrated in the north, although two regional 2-D transects span the region from the centre to the southern end of the bay. One of the regional 2-D refraction transects revealed a thick sedimentary package overlying oceanic crust along most of the profile, despite a lack of clear magnetic anomalies within Baffin Bay. To extrapolate the 2-D seismic refraction results offline and resolve the regional crustal structure across Baffin Bay, a constrained 3-D gravity inversion was undertaken. Bathymetry and depth to basement were used to constrain the 3-D inversion and the resolved crustal geometry from existing refraction lines was used to gauge the quality and reliability of the inverted model. The final inverted 3-D crustal structure model for Baffin Bay will provide useful constraints for basin studies and will shed light on its tectonic evolution.