ES0903  Observe an animation of volcanism along a rift zone.

Rift zones are divergent plate boundaries. Most of them occur along the seafloor as mid-ocean ridges. Where two plates are moving away from each other, molten rock rises to the surface, cools, and solidifies. Generally, each eruption of lava splits the rocks formed in the previous eruption, so the youngest rocks are always at the rift.

  !   Click the image to see the animation.
Jen Loomis, TERC