The origin and evolution of the Ninetyeast Ridge

The geological interpretation of seismic cross sections across the Ninetyea st Ridge allowed the oceanic crust to be recognized within its limits; subs equently, from the top to the bottom, it is composed of basalts, dolerites, gabbros, and serpentinized peridotites. Seismic and gravity data suggest t hat the ridge represents a fault-related structure, whose uplifting is caus ed by the serpentinization of peridotites. Two major stages are distinguish ed in the tectonic and magmatic evolution of the ridge.