Georgetown might be a dinky di part of northern Queensland these days but scientists are suggesting it may one time have been part of Canada before eventually colliding with the land near Mount Isa, scientists say.
Researchers at Curtin University say they have discovered rocks in the region that bear striking similarities to those found in North America, suggesting that part of northern Australia was actually part of North America 1.7 billion years ago.
The research paper in the journal “Geology” published by the Geological Society of America, concluded the rocks found in Georgetown have signatures unknown in Australia and instead have a surprising resemblance to rocks found in Canada today.
Curtin University PhD student Adam Nordsvan from the School of Earth and Planetary Sciences said the findings unlocked important information about the 1.6 billion year old supercontinent Nuna.
“Our research shows that about 1.7 billion years ago, Georgetown rocks were deposited into a shallow sea when the region was part of North America. Georgetown then broke away from North America and collided with the Mount Isa region of northern Australia around 100 million years later,” Mr Nordsvan said.
“This was a critical part of global continental reorganisation when almost all continents on Earth assembled to form the supercontinent called Nuna.”
Mr Nordsvan said they were able to determine this by using new sedimentological field data and new and existing geochronological data from Georgetown and Mount Isa. to reveal this unexpected information on the Australia continent.”
Researchers said when the supercontinent Nuna broke apart 300 million years later, the Georgetown area did not drift away and instead became a new piece of real estate permanently stuck to Australia.
Co-author John Curtin Distinguished Professor Zheng-Xiang Li, from Curtin’s School of Earth and Planetary Sciences, said the research also revealed new evidence of mountains around Georgetown and Mount Isa when the collision happened.
“Ongoing research by our team shows the final continental assembling process that led to the formation of the supercontinent Nuna was not a hard collision like India’s recent collision with Asia,” Professor Li said.
“This new finding is a key step in understanding how Earth’s first supercontinent Nuna may have formed, a subject still being pursued by our multidisciplinary team here at Curtin University.”
The research was co-authored by researchers from Curtin University, Monash University, and the Geological Survey of Queensland.