The theory of plate tectonics is a relatively new scientific concept.
The origins of the lavas pouring out of Earth's largest ongoing volcanic eruptions are being challenged in this week's Nature.
The eruptions are along the mid-ocean ridges that run for tens of thousands of miles though the deep sea.
These are spreading centers where the Earth's crust is being pulled apart and partially melted rock wells up to continuously fill the voids – building vast amounts of new oceanic crust. But no one is arguing that part of the story.
For the rest of the story: http://www.livescience.com/25115-rethinking-earths-most-massive-eruption.html