WE report here preliminary results from the detailed sampling of granitic basement at a depth of 4.000 m at the lower edge of the Armorican continental margin near 48°N and 12°W. We consider that we have sampled here the extreme lateral limit of the continental crust where local exposures emerge from under a cover of Cainozoic,Mesozoic and probable Palaeozoic sediments. [NOT CONTROLLED OCR]
Pautot Guy, Renard Vincent, Auffret Gérard-André, Pastouret Leo, de Charpal Olivier (1976). A granite cliff deep in the North Atlantic. Nature. 263 (5579). 669-672. https://archimer.ifremer.fr/doc/00000/5181/