Thermal evolution of the Central Atlantic passive margins: continental break-up above a Mesozoic super-plume

Publisher Website
Google Scholar
Abstract
A near synchronous Early Jurassic (200 Ma) magmatic event along the North American and West African passive continental margins can be explained by the upwelling of a large-scale mantle plume (super-plume) beneath the West African craton. Lateral deflection of the outflow from the plume to the NE by the ambient sub-lithospheric mantle flow could account for tholeiitic basaltic magmatism extending over a distance of nearly 5000 km from Brazil to southern Spain. Continental break-up is considered to occur above the stagnation streamline along which cooler material eroded from the base of the continental lithosphere by the plume is returned to the convecting mantle. The dynamic model is a scaled version of that recently proposed for the Hawaiian plume and satisfactorily explains the apparent lack of involvement of thermally anomalous mantle in the generation of Central Atlantic oceanic crust.