Nature Geoscience
More information about the region between the Earth’s upper and lower mantles has been revealed by an unique diamond discovered in the mines of Botswana. The area, also known as the transition zone or the 660 km discontinuity, is probably water-rich, according to a new research.
It may not sound like a major discovery to find large amounts of water below on a planet where water covers 71% of the surface. Though it is. Although the amount of liquid water on Earth’s surface may seem large, it is actually a small puddle in comparison to the amount of water present beneath the crust.
The planet’s crust, which is the outermost layer, is broken up, and the tectonic plates constantly rub against and at times slip under one another. According to Science Alert, water slips deeper within the earth and reaches the lower mantle.
The deep water cycle
This water, which has gradually slipped below the Earth’s surface, is brought back to the surface by volcanic activity. This water cycling, known as the “deep water cycle,” happens independently of the annual cycle that takes place on the surface.
Geologists research the deep water cycle to comprehend how it functions and to estimate how much water is below the surface. This is significant because the amount of water affects the planet’s geological processes. There is, however, a significant issue.
Despite technological advancements, we lack the equipment necessary to go under the Earth’s crust, therefore we must wait for signs to pop-out and then study them to make results.
Diamond from the transition zone
Tingting Gu, a mineral physicist at Purdue University and the Gemological Institute of New York, is a researcher who watches for such rare gems to appear on the surface of the planet. One such rare find was the diamond discovered in the Botswana mine, and Gu and her colleagues began investigating it to learn more about its origins.
The 12 mineral inclusions and a cluster of milky inclusions on the diamond were examined using micro-Raman spectroscopy and X-ray diffraction. They discovered a variety of minerals in these inclusions, including enstatite (a form of magnesium silicate), ferropericlase (magnesium/iron oxide), and ringwoodite (magnesium silicate) .
According to the information, the diamond likely developed 410 miles (660 km) beneath the Earth’s surface, in the transition zone. Additionally, scientists are aware that ringwoodite breaks down into the minerals ferropericlase and bridgmanite under extreme pressure. Bridgmanite transforms into enstatite at lower pressures, proving the diamond’s trip from the Earth’s core to the crust.
In addition, the ringwoodite and other mineral bruzites found in the diamond are hydrous in nature, suggesting that the region where it formed was water rich. There’s enough evidence that the Earth’s interior has absorbed far more water than previously thought that we may now be beginning to know where it’s going.
The research was published in the journal Nature Geoscience.
