New research analyzing pieces of the most ancient rocks on the planet adds some of the sharpest evidence yet that Earth’s crust was pushing and pulling in a manner similar to modern plate tectonics at least 3.25 billion years ago. The study also provides the earliest proof of when the planet’s magnetic north and south poles swapped places.  Read more about Prof. Roger Fu's and Alec Brenner's worok here: Harvard researchers provide stronger proof of plate tectonics billions of years ago – Harvard Gazette