ABSTRACT

The origin and age of topography along the west Greenland margin is a matter of continued debate. Analysis of seismic reflection profiles and 1D modelling of wells along the Greenland margin of Davis Strait demonstrate that the data are consistent with a model of ancient continental topography affected by Late Cretaceous-early Palaeocene rifting followed by thermal subsidence, where offshore Neogene tectonic uplift is not required. First order analysis of apatite fission track data from southeast Baffin Island reveals that samples experienced contemporaneous cooling from an array of initial temperatures. 1-D modelling suggests that cooling through the partial annealing zone occurred over discrete periods ranging from 100 to 300 Ma. Modelling the 3-D exhumation of a heterogeneous crust demonstrates that some of the variability in observed fission track ages could be attributed to thermal crustal heterogeneity. The results show that the observed data are consistent with a simple exhumation scenario where the present-day high topography is a remnant of that created during Palaeoproterozoic orogenies. In view of new geophysical constraints and newly assessed well data, a number of the exploration wells located on the conjugate west Greenland and Baffin/Labrador margins have been re-modelled to determine whether any new insights might be derived. Model results imply that southeast Baffin area was subject to more intense rifting prior to the onset of magmatism in the early Palaeocene. This in turn suggests that magmatism in the area was related to rifting and not linked to the arrival of a mantle plume at the beginning of the Palaeocene. The thermal histories presented here are consistent with those required for hydrocarbon generation.