A new study conducted by researchers from MIT and other universities has found that possibly a quadrillion (1015) tons of diamonds are buried deep below the surface of the Earth – about a 100 miles (160 km) deep, according to MIT’s website.
The Wonder of Cartonic Roots
The scientists think that the diamonds may be scattered inside cratonic roots, which are “the oldest and most immovable sections of rock that lie beneath the center of most continental tectonic plates”. Cratonic roots are shaped like inverted mountains and can reach “as deep as 200 miles (320 km) through the Earth’s crust and into its mantle”.
The study estimates that cratonic roots may contain 1%-2% diamonds, and considering the total volume of cratonic roots in the earth, it is estimated that there is a quadrillion (1015) tons of diamonds hidden there.
“Much More Diamonds” Than Previously Thought
Ulrich Faul, a research scientist in MIT’s Department of Earth, Atmospheric, and Planetary Sciences, explained: “This shows that diamond is not perhaps this exotic mineral, but on the [geological] scale of things, it’s relatively common. We can’t get at them, but still, there is much more diamond there than we have ever thought before”.
Faul and the team discovered this treasure trove following an anomaly in seismic data. In using seismic data to map the Earth’s interior, the scientists have been unable to explain a “curious anomaly” showing that “sound waves tend to speed up significantly when passing through the roots of ancient cratons”. They then built virtual rocks made from various combinations of minerals, and calculated how fast sound waves would travel through each virtual rock. Their conclusion: only one type of rock produced the same velocities as what the seismologists measured – one that contains 1%-2% diamond, in addition to peridotite and minor amounts of eclogite.
Faul concluded: “We went through all the different possibilities, from every angle, and this is the only one that’s left as a reasonable explanation”. According to MIT, “this scenario represents at least 1,000 times more diamond than people had previously expected”.
