]> Are neighboring ridges on different tectonic plates which have similar seismic characteristics. "Based on similar seismic velocity gradients of the lavas of the Carnegie, Cocos and Malpelos Ridges there is evidence that the hotspot activity has been the result of a single long mantle melt rather than multiple periods of activity and dormancy." [Wikipedia] An Ophiolite is a section of the Earth's oceanic crust and the underlying upper mantle that has been uplifted or emplaced to be exposed within continental crustal rocks. [Wikipedia] A location where belts of high pressure, low temperature metamorphism on the oceanic side are associated with belts of high pressure, high temperature metamorphism on the continent side. [Wikipedia] A rift valley is a linear-shaped lowland between highlands or mountain ranges created by the action of a geologic rift or fault. [Wikipedia] A flood basalt or trap basalt is the result of a giant volcanic eruption or series of eruptions that coats large stretches of land or the ocean floor with basalt lava. Flood basalts have occurred on continental scales (large igneous provinces) in prehistory, creating great plateaus and mountain ranges. [Wikipedia]