Thermal and tectonic evolution of the Falkland Islands: implications for hydrocarbon exploration in the adjacent offshore region

Apatite fission track and vitrinite reflectance data combine to suggest that the Falkland Islands experienced three discrete episodes of heating and cooling during the Phanerozoic, each of which can be related to major changes in the plate tectonic setting of the islands. Combined with published data from the adjacent offshore areas, the results provide unique insights into the behaviour of the region during the phases of convergent and divergent tectonic movements that have affected the region since the Permian. Initial cooling of the Falkland Islands in the Late Permian was initially restricted to West Falkland, and was the result of differential uplift and erosion of West Falkland relative to East Falkland, coinciding with D2 Gondwanian deformation. Subsequent Early Jurassic cooling of both East and West Falkland was associated with plume-related thermal uplift preceding the separation of East and West Gondwana and the development of the Falkland Plateau Basin. The Falkland Islands experienced renewed heating during the Mesozoic, probably due to increased burial, suggesting that the offshore basins originally extended onto the present onshore region. Late Cretaceous/Early Tertiary cooling of the Falkland Islands was contemporaneous with the development of a transpressional plate boundary along the southern margin of the Falkland Plateau resulting in erosion of the islands that were situated on a flexural forebulge.