Rodinia supercontinent more ancient than Pangea
Many people know about Pangea – the ancient supercontinent thought to have broken up 250 to 300 million years ago.
Paul Myrow: Because you can’t go back any further than the collection of mass that you see as Pangea, there’s no way to reconstruct what pieces were where on the globe, that far back.
That’s Paul Myrow, a geologist at Colorado College. He and colleagues are trying to look back approximately 800 million years, to an older supercontinent, known as Rodinia.
Paul Myrow: There’s been this ongoing debate about the position of various continents within this supercontinent Rodinia. We do know that North America sat in the center of this continent. But what we’re unsure of is what sat off the western coast of North America?
The geologists dated minerals found in Antarctica’s mountains and glacial debris. Both were 1.4 billion years old, with similar chemical composition.
Paul Myrow: Those turned out to be the key to linking East Antarctica and North America. The reason is, that if you look at North America today, there’s a big swath of granite that is about 1.4 billion years old. That granite is found across North America, but it really isn’t found on any other continents.
Myrow said that evidence fit the southwestern U.S. next to Antarctica – one piece of the puzzle.
Thanks for a very interesting and informative article. I just realized the relatively short history we have suggests that continents have formed and reformed in various shapes and combinations throughout the Earth’s lifetime. Perhaps there was no “supercontinent”; only an endless series of collisions and rifting.
It is fascinating that this continental drift has occurred through the history of the world. What is even more amazing is that scientists can find evidence of what happened so many millions of years ago and piece it all together!