A study has discovered that “an invaluable treasure trove of diamonds” may be hidden near the Earth’s core.

Scientists at Arizona State University say that the heat and pressure at the boundary of the planet’s core mantle can create an impressive wealth of diamonds below the surface.

A new study has revealed that a layer of diamond is found near the Earth’s core.

In the Earth’s core, the oceanic crust above the tectonic plates is falling inland in a process called subduction. This crust contains hydrated minerals that sometimes extend to the boundaries of the core and mantle.

The Earth’s core is the largest store of carbon on Earth – about 90% of it is buried there. Scientists have shown that oceanic crust that sits on tectonic plates and falls ashore through subduction contains hydrated minerals and can sometimes sink into the core mantle boundary.

The temperature at the core-mantle boundary is at least twice that of the lava, high enough that water can be released from the hydrated minerals. Therefore, a chemical reaction similar to the rusting of iron can occur at the boundary of the Earth’s mantle.

Recently, Byungkwan Koo, PhD, from Arizona State University, and colleagues at Argonne National Laboratory conducted experiments at the Advanced Photon Source at the Earth’s core boundary, which fuses iron-carbon and water alloys at expected pressures. and temperature. Smelting of iron and carbon alloys.

They found that water and metals react to form iron oxides and iron hydroxides, just as they do in rust on Earth’s surface.

However, they found that for core-mantle boundary conditions, carbon comes out of iron-metal alloys and forms diamonds.

“At the boundary between the silicate mantle and the mineral core, at a depth of 3,000 km, the temperature reaches about 7,000 degrees Fahrenheit, which is high enough that most of the minerals (H2O) lost in the water are lost ,” said Dan Shim. Professor at Arizona State University for Earth and Space Studies. obtained in atomic-scale structures. In fact, the temperature is high enough for some metals to melt under these conditions.”

Since carbon is an iron-loving element, a large amount of carbon is expected in the core, while the mantle is believed to have a relatively low carbon content. But scientists have discovered that there is more carbon in the mantle than expected.

“Under the expected pressure of Earth’s core boundary, mixtures of hydrogen with liquid metallic iron seem to reduce the solubility of other light elements in the core. Therefore, the solubility of carbon that is likely to be found in the Earth’s core decreases locally as hydrogen enters the core,” he explained. shim. “From the core mantle (through dehydration). At the pressure and temperature conditions of Earth’s core boundary, the stable form of carbon is diamond. So when liquid carbon escapes into the mantle from the outer core, it turns into diamond.”

“Carbon is an essential element for life and plays an important role in many geological processes. The new discovery of the mechanism of carbon transfer from the core to the mantle will shed light on the understanding of the carbon cycle in the deep Earth. This is all the more exciting given that diamond formation at the core-mantle boundary can be carried out.” “Billions of years have passed since subduction began on this planet.”

Kue’s new work shows that carbon seeping from the core into the mantle through this diamond-forming process can provide enough carbon to explain the high carbon abundance in the mantle.

source: phys.org