Tectonic variation and structural evolution of the West Greenland continental margin

Because of its geographic extent of over 2500 km (1553 mi), the West Greenland margin provides a much understudied example of a divergent continental margin, both with respect to hydrocarbon exploration and academic studies. A seismic interpretation study of representative two-dimensional reflection profiles from the Labrador Sea, Davis Strait, and Baffin Bay was undertaken to identify sedimentary and structural components to elucidate the tectonic development of the margin. Nine horizons were interpreted from six representative seismic lines in the area. Margin-scale tectono-stratigraphy was derived from isochron maps, the geometry of mappable faults and their associated stratal architecture. Rifting began in Early to Late Cretaceous at ca. 145–130 Ma, which was followed by two pulses of volcanism in Eocene and Paleocene ages. The transition to the drift stage includes a typical subsidence phase but also erosion, uplift, and deposition of Neogene postrift packages. The shift in the position of depocenters in the Davis Strait and the Labrador Sea during Paleocene and Miocene times is evidence for structural modification of the basin bounding faults. Drift stage deformation suggests a possible anticlockwise rotation in the orientation of the spreading axis in Baffin Bay culminating in an ultraslow sea-floor spreading. Sea-floor spreading on the West Greenland margin started in the south at 70 Ma in the Labrador Sea and propagated northward into the Baffin Bay by 60 Ma. Prospective petroleum systems include thick Cretaceous age strata, with structural traps provided by grabens and inversion structures. Our structural model provides insight into a margin that is highly variable in its structural configuration, further modified by other processes such as magma-assisted rifting that may result in elevated regional heat flow, which has considerable impact on hydrocarbon maturation. Further constraining the implications of heat flow associated with volcanic activities in comparison to that associated with lithospheric stretching will be critical in future exploration.