Earths tectonic plates were in motion 400 million years than previously thought.

Scientists from Harvard University who examined rocks over 3 billion years old discovered that Earth’s tectonic plates move today in the same way that they did between 2 and 4 billion years ago, as published in the journal Science Advances.

The findings suggest that the continents settled in place and sustained life much earlier than previously thought, and give insight into plate tectonics on other planets. As it turns out, life on Earth would not have been possible without plate tectonics. Now we have understood that this occurred much sooner than initially thought.

A constant question in geology is when exactly did Earth’s tectonic plates began to push and pull in a process that helped the planet evolve and shaped its continents as they exist today. Some researchers theorize that it happened about 4 billion years ago, while others think it was closer to 1 billion years ago.

To come to the bottom of this geosocial debate, a research team led by Harvard scientists searched for clues in ancient rocks over 3 billion years old in Australia and South Africa and found that Earth’s tectonic plates were already in motion at least 3.2 billion years ago during Earth’s early years.

Geologist Alec Brenner of Harvard University and Roger Fu measured the magnetic orientations of iron-bearing minerals in the Honeyeater Basalt, a layer of rock that is thought to have formed between 3.19 billion and 3.18 billion years ago. The basalt is part of the East Pilbara Craton, an ancient bit of continent in Western Australia that includes rocks as old as 3.5 billion years.

Researchers discovered that this particular craton, was already in motion between 3.35 billion and 3.18 billion years ago, drifting around the planet at a rate of approximately 2.5 centimeters per year. Researchers discovered that this rate is, in fact, comparable to present speeds of plate motions. Read the free article.