Vema fracture zone

From temperature data gathered from the deep ocean on the German Meteor expedition (1925–1927) Georg Wüst already suspected that there should be a passage through the Mid-Atlantic Ridge around latitude 9 North.

Hamilton on board RV Vema, with additional surveying taking place in the years 1959–1960.

This narrow ridge must have risen as a single vertical slab 6.6 million years ago.

While the transform valley of the Vema fracture zone has a V-shaped profile, the next fracture zone to the south has a steep vertical wall on its southern side rising from a horizontal valley bottom.

The Vema transform was thus extended by 40 km, while the Lema fracture zone was reduced to zero offset.