Rifting and evolution of the Labrador–Baffin Seaway

The evolution of the 2000 km long Mesozoic rift system underlying the Labrador-Baffin Seaway is described, with emphasis on results from geophysical data sets, which provide the timing, sediment thickness, and crustal structure of the system. The data sets include seismic reflection and refraction, gravity, and magnetic data, with additional constraints provided by near-surface geology and well data. Many features that characterize rift systems globally are displayed, including: wide and narrow rift zones; magma-rich and magma-poor margin segments; exhumation of continental mantle in distal, magma-poor zones; and occurences of thick basalts, associated with the development of seaward-dipping reflectors, and magmatic under-plating. The magma-rich regions were affected by Paleogene volcanism, perhaps associated with a hotspot or plume. Plate reconstructions help elucidate the plate tectonic history and modes of rifting in the region; however, many questions remain unanswered with respect to this rift system.