Early rifting of Gondwana : Conclusions from the crustal structure of the Falkland Plateau

Abstract

During the Jurassic, the Falkland Plateau was part of Gondwana and occupied a position between the African, South American and Antarctic plates. Several contrasting kinematic models exist for the breakup of Gondwana because of the currently unknown crustal structure of the plateau. In this thesis, I present the results of recently acquired wide-angle seismic data along the entire plateau that provide sound constraints on its role in geodynamic reconstructions. The new data show that the Falkland Plateau Basin consists of up to 20 km thick oceanic crust. Maurice Ewing Bank is an up to 29 km thick continental fragment, which was directly attached to the Falkland Islands block during the Jurassic. Rifting between the Falkland Islands and the Maurice Ewing Bank started at 178 Ma and ceased at around 154 Ma.