Deep drilling results of Leg 47b (Galicia Bank area) in the framework of the early evolution of the North Atlantic Ocean

Lithologic and stratigraphic evidence from D.S.D.P. Site 398 (3910 m water depth, 1740 m total penetration) and regional seismic reflexion data are placed in the context of the early tectonic evolution of the North Atlantic ocean. The morphology of the western Iberian continental margin is the result of two main tensional episodes dated Permo-Lias and Upper Jurassic - Lower Cretaceous, during which the initial basins between Grand Banks and Iberia were created by subsidence and tilting of continental blocks. A limited oceanic opening had probably occurred in Jurassic time between these two tensional episodes. There was no relative motion during Lower Cretaceous between North America and Iberia. [NOT CONTROLLED OCR]