Eduction (geology)

In geology, eduction is a process in which the Earth crust spreads sideways, exposing deep-seated rocks.

It is prominent in middle layers of the Himalayas, where gravity pushes the mountains down. Together with a high grade of erosion, this activity brings deep rocks to the surface, many from more than a depth of 100 km. The unusually fast elevation preserves rare metastable minerals, e.g. diamonds and coesite.