A water-rich mineral embedded in a Brazilian diamond provides further evidence that a vast water layer lies deep beneath the surface of the Earth. Canadian geologists discovered the mineral, which may have formed in a massive watery region within the Earth's layer known as the transition zone, which lies between 410 to 660 kilometers below the Earth's surface.
Water makes up approximately 1.5 percent of the weight of the mineral — known as ringwoodite — which a University of Alberta graduate student found embedded in a commercially useless brown diamond mined from the Mata Grosso region of Brazil. The journal Nature published the results of ringwoodite analysis.
“This sample really provides extremely strong confirmation that there are local wet spots deep in the Earth in this area,” said Graham Pearson of the University of Alberta in a press release. “That particular zone in the Earth, the transition zone, might have as much water as all the world’s oceans put together. One of the reasons the Earth is such a dynamic planet is the presence of some water in its interior. Water changes everything about the way a planet works.”
Geologists have debated the existence of water in the transition zone, but evidence seems to be mounting that the Earth has a vast amount of water in the mantle, the region between the core and the crust.
Another study published in Nature noted that the rocks of mid-ocean islands contained distinctive chemical signatures. The rocks’ compositions suggested that these islands may have formed from liquid rock, or magma, squeezed up from the watery transition zone and dehydrated as it moved to the surface.
Photo: Graham Pearson holds a diamond that contains the water-rich mineral “ringwoodite.” A new discovery that yields new clues about the presence of large amounts of water deep beneath the Earth. Photo: Richard Siemens/University of Alberta