The Atlantis Massif is a prominent undersea massif, a dome-shaped region approximately 10 mi. (16 km) across and about 14,000 ft. (4250 m) high, in the North Atlantic Ocean at approximately 30°N latitude just east of the intersection of the Mid-Atlantic Ridge with the Atlantis Transform Fault .

The massif was formed approximately 1.5-2.0 million years ago. Geologic studies of the massif have indicated that it is not composed of the black basalt typical of the ocean floor, but rather of dense green peridotite usually found in the mantle. The central dome is also corrugated and striated in a way that is representative of an exposed ultramafic core complex. It is believed that the massif was formed underneath the nearby Mid-Atlantic Ridge but was pulled underneath the ridge during the movement of the plates.

The Lost City Hydrothermal Field is near the summit of the ridge.

External links

• View of the Massif
• University of Washington: The Atlantis Massif
• Harvard University: Geology of the Atlantis Massif