The oceanic crust exposed on the Gorringe Bank (SW Portugal) presents a laccolith-like body of gabbros, 500 m thick by 50 km long, within mantle peridotites. It also shows rare tholeiitic dikes and pillow-lavas resting locally directly over the peridotites. Gabbros, that crystallized in a closed system, subsequently underwent strong deformation in highto low-temperature conditions, in a west to east extensional flat shear zone system. This massif would likely be formed during the early stages of oceanic spreading, at the end of continental rifting. This is in agreement with kinematic reconstructions for the North Atlantic Ocean.
