The Demerara and Guinea Plateaus were part of the residual eastern part of the Gondwanaland when they have rifted apart from the North America in Middle Jurassic. Now the Demerara Plateau is located in the northwest corner of the equatorial segment of the Atlantic Ocean. It has rifted from the Guinea Plateau on the African margin during the Early Cretaceous opening of the Central Atlantic. The episode of Early Cretaceous compression predated the passive subsidence of the conjugate plateaus during the drift phase of the African and South American separation. Early Cretaceous compression produced a significant deformation of the southern edge of Guinea Plateau and north–northeast edge of the Demerara Plateau. Our earlier plate tectonic modeling used rigid African and South America plates and have estimated at least 20–50 km of shortening on Demerara Plateau during Early Cretaceous. It is topped by Albian unconformity, which according to our modeling has removed up to 6 km of sediments from the Demerara Plateau.
Our team of co-authors collaborated on the studies of the Atlantic margin for over a decade revising and linking our discrete observations together into a cohesive picture of South Atlantic evolution from continental extension into oceanic spreading. Using our seismic and gravity interpretation supported by drilling results we gradually built our preferred plate reconstruction model for South Atlantic opening. Our interpretation is focused on most critical moments of the South Atlantic geologic history from Late Jurassic to Upper Cretaceous. Modifications in the Plate Model adjusted the Limit of Oceanic Crust (LOC) up to 100 km outboard in some instances, creating room for multiple exploration blocks and new play concepts to be defined along the margin.