Researchers have found evidence that a part of Australia was once connected to North America, providing further insight to the ancient supercontinent known as Nuna.
It may be hard to imagine that a small town in Australia was once connected to what is now known as Canada, but the proof is found in rocks that scientists have discovered.
Rocks Prove Australia Once Connected To North America
In Georgetown, which is located in the northern part of Queensland, researchers from Curtin University discovered a section of rocks unlike any others in Australia. However, the rocks share striking similarities with rocks in North America, which suggested that the two continents were once connected.
The researchers, which published their findings in the Geology journal of the Geological Society of America, claimed that the evidence uncovered important information about Nuna.
The supercontinent Nuna, also known as Columbia, is believed to have existed from around 2.5 billion years to 1.5 billion years ago. It was a precursor to the more widely known Pangaea supercontinent, which broke apart around 175 million years ago.
"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," said Adam Nordsvan, a PhD student from Curtin University's School of Earth and Planetary Sciences.
The researchers determined that after Nuna broke apart about 300 million years later, the Georgetown land stayed in place, sticking with Australia.
In addition, the researchers noted that the discovery provided new information on the mountains that formed when Georgetown collided with Australia.
According to the study's coauthor Zheng-Xiang Li, who is a John Curtin distinguished professor and also from Curtin University's School of Earth and Planetary Sciences, the mountain belt would not be as high as the Himalayas. This meant that the formation of Nuna did not end with a hard collision unlike the collision of India with Asia.
The Hidden Continent Of Zealandia
The supercontinent Nuna is long gone, but the supercontinent Gondwana, which broke up about 180 million years ago, is still around through the hidden continent Zealandia.
Zealandia, which was discovered about a year ago, covers the southwest region of the Pacific Ocean to the east of Australia and is 94 percent submerged. An expedition to Zealandia revealed that the hidden continent was not always as deep as it is today, and its seabed was affected by the formation of the Pacific Ring of Fire.