Abstract

The Mesozoic to present evolution of the central Atlantic realm is interpreted as a two-stage tectonomagmatic scenario involving long-lived asymmetric mantle upwelling phenomena and magmatism within its eastern margin. The first, a pre-drift tholeiitic stage of Triassic-Jurassic age, resulted from the interaction between several elements: (1) a thinned, weakened corridor along the collapsed southern branch of the Variscan belt between eastern North America and western North Africa; (2) a central Atlantic plume located in the triple junction between Africa, North America, and South America; (3) a progressive asymmetric continental breakup between northwest Africa and North America characterized by detachment systems; and (4) a highly thinned European realm pervaded by rift-type basins that we interpret as a large thin-spot-type domain. These conditions would have induced north-northeast–directed large-scale sublithospheric plume channeling from the central Atlantic plume site to the European large thin-spot, leading to widespread early tholeiitic magmatism (Triassic-Jurrassic) within a giant irregular zone of ∼3000 × 4000 km. Plume activity and chaneling continued afterward during a Cretaceous to present second tectonomagmatic stage (passive margin alkaline stage) leading to the onset of alkaline magmatism along a general north-northeast trend in the eastern Atlantic margin (Late Cretaceous) and Europe (Paleocene–Oligocene). As a whole, a north-northeasst–directed propagating magmatic vector can be defined from the Mesozoic to the present.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.