Earth was flat and almost entirely covered by water, scientists believe

EARTH 4.4BN years ago was flat and almost covered in water with just a few small islands, research suggests.

Scientists came to the conclusion after analysing tiny zircon mineral grains from a region of Western Australia containing the oldest rocks ever found.

Lead researcher Dr Antony Burnham, from The Australian National University, said: “The history of the Earth is like a book with its first chapter ripped out with no surviving rocks from the very early period, but we’ve used these trace elements of zircon to build a profile of the world at that time. “Our research indicates there were no mountains and continental collisions during Earth’s first 700m years or more of existence – it was a much more quiet and dull place. “Our findings also showed that there are strong similarities with zircon from the types of rocks that predominated for the following 1.5bn years, suggesting that it took the Earth a long time to evolve into the planet that we know today.”

The team, whose findings are reported in the journal

conducted a study of the grains looking for clues to their formation.

They believe that the zircon was created by melting old igneous rocks rather than sediments. “Sediment melting is characteristic of major continental collisions, such as the Himalayas, so it appears that such events did not occur during these early stages of Earth’s history,” said Dr Burnham.

The zircon grains, preserved in sandstone rocks in the Jack Hills, date back to when the Earth was 160m years old.

The research fits in with the “Cool Early Earth” theory that suggests a cool period followed the extreme conditions of our planet’s earliest history as it formed from violent collisions.