The breakup of the Central Atlantic is known to terminate around 190Myrs while the CAMP (Central Atlantic Magmatic Province) activity was ending. A dense seismic dataset, acquired along the MSG Basin, provide detailed images of the continent-ocean transition and oceanic crust architecture.

Five oceanic/magmatic crust facies were described and mapped. They reveal, in the north, a progressive increase of magmatism. In the south, a 9-11 km thick magmatic crust is observed. Locally, a peculiar facies, with intra-oceanic SDR, is observed and correlated with the formation of the African Black Spur Magnetic Anomaly (ABSMA). In the North, seismic data suggest a typical magma-poor margin profile with an extremely thinned continental crust and mantle exhumation at the COT. In the South, the continental crust thinning is associated with SDR emplacement, and a thick magmatic crust emplaced in the distal domain, which is typical of magma-rich margins.

Therefore, in the South, the breakup was forced through the continental crust due to the remnant activity of a CAMP derive hotspot. In the North, the magmatic input seems directly linked to the plate motion in the exception of the ABSMA during which, despite a brief and sudden acceleration of the plate motion, an increase of mantle temperature is needed to explain the change in oceanic crust thickness and facies.

This evolution emphasizes that the architecture, and thus processes leading to breakup, can vary considering the influence of thermal vertical forces and mechanical horizontal forces, both being necessary for a rift to succeed.