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The tremor was felt up to north as Cairns, south as far as Maroochydore and west of Charters Towers. Facebook/Mackay & District Weather Updates

A part of Australia had been attached to North America 1.7 billion years ago, new research suggests. Researchers have discovered rocks in Down Under that bear similarity to those from North America.

Curtin University researchers examined rocks from Georgetown, Queensland, Australia, which is about 250 miles west of Cairns in the northeastern part of the continent. Sandstone sedimentary rocks recently unearthed are not “native” to present-day Australia.

It is believed that a region of what is now known as modern-day Australia was once attached to North America. The link broke away aeons ago. A chunk may have possibly crashed into what is now known as Australia, forming the "supercontinent" Nuna after it drifted around for some 100 million years.

“This was a critical part of global continental reorganization when almost all continents on Earth assembled to form the supercontinent called Nuna," lead study author and Curtin University PhD student Adam Nordsvan from the School of Earth and Planetary Sciences said in a statement. He explained that the research shows Georgetown rocks were deposited into a sea when the region was part of North America before it broke away and collided with the Mount Isa region of northern Australia.

It was previously suggested, based on past research, that northeast Australia was near North America, Siberia or North China when Nuna was formed. Mountain ranges can be formed from colliding landmasses.

Researchers of the recent study said they discovered evidence of mountains forming when Georgetown rammed into the rest of Australia. Curtin’s School of Earth and Planetary Science’s Zheng-Xiang Li, a co-author of the study, said that their team’s ongoing research shows that the mountain belt would not have been very high.

The researchers used new and existing geochronological data from both Georgetown and Mount Isa and new sedimentological field data. They concluded that the Georgetown area broke away from North America billions of years ago. They shared their findings in the journal Geology, published by the Geological Society of America.

The recent finding is viewed as a key step in understanding how Earth’s first supercontinent Nuna, sometimes referred to as Columbia, may have formed. Scientists first proposed the existence of Nuna in 2002.

Researchers from Curtin University, Monash University, and the Geological Survey of Queensland co-authored the new report. The full research paper, “Laurentian crust in northeast Australia: Implications for the assembly of the supercontinent Nuna,” can be viewed online at pubs.geoscienceworld.org.