Georgetown, in northern Queensland (Australia), was once part of North America say, researchers.
That is what seems to suggest the finding and subsequent study of a series of rocks and fossils in the area.
If so, it would mean that Australia was connected to Canada about 1.7 billion years ago.
The idea that the two continents were once connected is not surprising.
Such Speculations have existed since the late 1970s, when scientists proposed that this connection dated back to the continent of Rodinia, about 1.13 billion years ago.
However, and even under that theory, a date was missing.
The findings in Georgetown, a small town in northeastern Australia, now seem to be a boost to that theory.
The rocks found in Georgetown are different from all other rocks on the Australian continent.
However, they show enormous similarities to ancient rocks found in Canada, in the exposed section of the continental crust called the Canadian Shield.
An unexpected finding, according to researchers at Curtin University, Monash University and the Queensland Geological Survey in Australia, which reveals something about the composition of the ancient supercontinent Nuna.
According to Adam Nordsvan, principal investigator: “Our research shows that about 1,700 million years ago, Georgetown rocks were deposited in shallow water when the region was part of North America. Georgetown separated from North America and collided with the Mount Isa region in northern Australia some 100 million years later. This was a fundamental part of the global, continental reorganization when almost all the continents on Earth came together to form the supercontinent called Nuna.”
The last time the continents were close to each other was the great supercontinent known as Pangea, which split about 175 million years ago.
However, before Pangea, the planet went through several configurations of supercontinents, one of which was Nuna, also called Columbia, which existed about 2,500 million to 1,500 million years ago.
The team of researchers came to this conclusion after examining sedimentological data, and new existing geochronological data from Georgetown and Mount Isa, another remote city in northeastern Australia, and comparing everything to rocks from Canada.
“Ongoing research by our team shows that this mountain belt, in contrast to the Himalayas, would not have been very high, suggesting 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,” said co-author Zheng-Xiang Li.
“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 has been published in the journal Geology.
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