U.S. and Australian scientists have found evidence that environmental conditions on Earth's early days resembled those of the present day.

Using the mineral zircon, scientists at Rensselaer Polytechnic Institute in Troy, N.Y., and at the Australian National University said they have been able to determine conditions on Earth, within 200 million years of its formation, featured liquid-water oceans and continental crust.

The scientists developed a new thermometer that measures the titanium content of zircon crystals to determine their crystallization temperature.

Zircons are tiny crystals embedded in rock and are the oldest known materials on Earth. They pre-date by 400 million years the oldest known rocks. The crystals therefore provide a window into the planet's earliest history and have been used to date the assembly and movement of continents and oceans.

"Zircons allow us to go farther back in geologic time because they survive processes that rocks do not," the scientists said. "Although they are only a fraction of a millimeter in size, zircons hold a wealth of information about the very earliest history of Earth."

ScienceDaily

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