Mid-ocean ridges are sites where oceanic lithosphere is created. They are hotter and therefore stand higher than older, cooler lithosphere. As a result, the base of the lithosphere slopes away from t [..]

 

See metamorphism, regional

 The ocean that opened between the continents of Gondwana and a collection of micro-plates including “Avalonia” during the Variscan Orogeny.

see mantle plume

see lithospheric plate

ity

 Incomplete melting of rock to produce magma of a different composition from the original rock. Partial melting of the mantle produces basaltic magma. When partial melting occurs, the minerals with th [..]

 A coarse grained, dark coloured igneous rock consisting mainly of olivine and pyroxene, which is believed to be the major constituent of the mantle.

The name given by Wegener to the supercontinent that he proposed to explain the ice distribution at 300 Ma. It came into being during the Permian and existed for around 40 million years. It was a sing [..]