A series of left-lateral faults displace the axis of the Mid-Atlantic Ridge in the equatorial Atlantic. Two of the most prominent of these faults are the Romanche and Chain Fracture Zones. The ridge crest is offset 180 miles by the Chain Fracture Zone. The Vema Depth of 4106 fm is the maximum depth observed in the Romanche Trench. The floor of the trench is locally smoothed by sediments gravity transported from adjacent areas. Allochthonous fossils occur in cores from the trench floor. Scour by bottom currents is apparent in photographs and in the character of the sediments obtained by coring.