It was one of the Earth's momentous times. Continents collided. Volcanoes erupted. Ocean currents shifted. Species ran amok.
For some time now, scientists have understood that the earth’s crust is divided into plates that move about at the rate of a few inches a year. Over time, this movement will form mountain ranges and volcanoes. They have also known that the earth’s mantle, the layer between the earth’s crust and core, was the [...]