Historical rocks reveal how water helped form the world

New Curtin-led analysis has revealed that water performed a far larger function than beforehand thought in shaping Earth’s first continents, remodeling the planet’s early crust and serving to to construct the landmasses we see right this moment.

In an article printed in Communications Earth & Surroundings, the analysis workforce studied 1.6-billion-year-old rocks from the Georgetown Inlier in northeast Queensland—residence to a number of the best-preserved items of continental crust on Earth.

Lead researcher Dr. Silvia Volante, who accomplished the analysis at Curtin’s Faculty of Earth and Planetary Sciences however is now based mostly at ETH Zurich in Switzerland, mentioned the findings may redefine our understanding of water’s function within the Earth’s early evolution and its significance in shaping the continents we see right this moment.

“Within the early days of our planet, volcanic rocks erupted on the ocean floor and have been then altered by scorching water as they cooled down and solidified. Over time, these water-rich rocks have been buried deep inside the Earth’s crust, the place the introduction of further water brought on them to partially soften at temperatures starting from 700°C to 750°C,” Dr. Volante mentioned.

“By analyzing the oxygen ranges inside the rocks, the analysis workforce discovered a transparent distinction between the unique volcanic rocks and the granitic rocks they changed into—suggesting a further supply of water from deep inside the Earth’s mantle.

“The 2 sources of water which fashioned the continental crust rocks—one from the volcanic rocks themselves, and extra surprisingly additionally from deep inside the Earth—fueled a chain reaction of melting which lasted tens of millions of years and helped kind the constructing blocks of the continents we reside on right this moment.”

Co-author ARC Laureate Fellow John Curtin Distinguished Emeritus Professor Zheng Xiang Li, additionally from Curtin’s Faculty of Earth and Planetary Sciences, mentioned the workforce was lucky to have the ability to research Australia’s historic rocks, which supply a uncommon and well-preserved report of how the Earth fashioned.

“We had an unbelievable alternative to work in distinctive places such because the Georgetown Inlier, which is without doubt one of the solely locations on the planet the place we will see all levels of continental crust formation locked in billion-year-old rock,” Professor Li mentioned.

“Our subsequent step is to analyze whether or not comparable water-based melting processes occurred in even older crust fragments. Discovering extra well-preserved examples will assist present simply how essential water motion within the Earth’s mantle was in shaping our planet’s early panorama.”