It also has opaque white patches on its upper mantle.

The crust and the upper mantle make up the lithosphere.

This suggests a hot upper mantle in the same region.

How is evolution of the continents linked to processes in the upper mantle?

There are two main zones in the upper mantle.

Below the lithosphere the upper mantle becomes notably more plastic.

He believes the plumes formed at the base of the upper mantle, 400 miles down, rather than far deeper.

The boundary between the mantle's upper and lower layers is at a depth of 400 miles.

Thus, the upper mantle can only flow very slowly.

This concentration is comparable with that of magma in Earth's upper mantle.