How did rocks from the Grand Canyon end up 13,500km away in Australia?
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How did rocks from the Grand Canyon end up 13,500km away in Australia?

CENTRAL Arizona is a good 13,500 kilometres from the Australian island of Tasmania. Being a third of the world away, you wouldn’t think the two would have much in common in terms of geology – but you would be wrong.

Scientists in Tasmania have found ancient rocks that have the same minerals and geochemical make-up as some of the oldest rock layers found in natural wonder of the world, the Grand Canyon.

While this seems perplexing, the two regions were actually part of one supercontinent around one billion years ago.

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Named Rodinia, this mega landmass is thought to have contained all of today’s continental plates.

The research, published in the journal Geology, found the rocks were aged between 1.1 and 1.2 billion years old and their geochemistry is more closely related to those in the Grand Canyon which dates back a whopping 1.5 billion.

Discovery of the rocks will help scientists better understand how the continents fit together to form Rodinia all those years ago.


Rocky Cape National Park, Tasmania, Australia, where the strange rocks were found. Source: Facebook – Geoff Murray

“[This] paper shows that Tasmania holds the key to tying together the tectonic geography of the time,” Alan Collins at the University of Adelaide, Australia, told New Scientist. “It’s really a good link and tie that allows us to build full plate models of the ancient Earth.”

The continental plates are constantly moving – although you’d be hard pressed to notice. Australia is currently moving north towards Asia by up to seven centimetres per year. Not exactly lightning speed but significant enough for scientists to believe that another supercontinent is in our future.

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In the next 50 million to 200 million years, scientists believe all seven continents will once again be connected in a mega landmass called Amasia.

Rodinia is not the be confused with Pangea, the most famous and most recent of planet Earth’s supercontinents.

The planet has had several of these over its 4.5-billion-year existence. The discovery of similar fossils scattered across the world, from South Africa, India and Australia, lent evidence to the existence of Pangea.