Paleomagnetic data from western Anatolia and from the island of Lesbos demonstrate significant counterclockwise, clockwise or null rotations of coherent blocks which occurred during the neotectonic period. These results suggest that the brittle carapace of the lithosphere may not everywhere follow the motion of the ductile lower part but that its movement arises from adjustment to the extensional tectonic regime. ¿ American Geophysical Union 1987