The Earth Contents

2. Plate Tectonics

Constructive plate motion occurs where oceanic crustal plates are diverging

Where oceanic crustal plates are diverging, new oceanic crust is created by undersea volcanic activity which brings up fresh basaltic material from the underlying mantle. These sites are recognised in the oceans by the presence of a prominent ridge, termed the mid-ocean ridge, which occurs in the gap between the separating plates. Movement between plates is extremely slow and occurs at only a few centimetres a year.

What type of plate motion would you associate with the formation of mid-ocean ridges?