Basin evolution in the Davis Strait area (west Greenland and conjugate east Baffin/Labrador passive margins) from thermostratigraphic and subsidence modelling of well data: implications for tectonic evolution and petroleum systems

The sedimentary basins of the Davis Strait area developed mainly as a result of late Mesozoic and Cenozoic rifting processes that led to the formation of the West Greenland, southeast Baffin, and east Labrador continental margins. Recently acquired regional geophysical data in the area provide considerable new constraints on sedimentary basin and crustal thicknesses as well as plate kinematic reconstructions. Further, the chrono-stratigraphy and vitrinite reflectance data for several of the northern Labrador margin wells have been re-correlated and corrected. Given this, new 1-D models for the subsidence and thermal evolution of a number of the exploration wells located on the conjugate West Greenland and east Baffin/Labrador margins have been computed. Model predictions based on lithospheric extension agree well with observed stratigraphic and thermal data from West Greenland, southeast Baffin, and east Labrador wells. Calculated stretching factors for the wells are remarkably similar, except for those off southeast Baffin Island, which are higher. This implies that this area was subject to more intense rifting prior to the onset of magmatism in the early Paleocene. In turn, this may suggest that the magmatism was related to rifting and not, as commonly believed, linked to the arrival of a mantle plume at the beginning of the Paleocene. The modelled thermal histories indicate that maximum subsurface temperatures occurred at different times throughout the Cenozoic, depending mainly on the sedimentation (burial) histories, surface temperatures, and heat flow. Prediction of hydrocarbon generation in the area must therefore include these parameters.