Scientific breakthrough may help pinpoint precious diamond mines

Diamond eruptions have been found to mimic the rhythm of the supercontinents, which assemble and break up over time. The most recent was Pangaea, which was made up of every continent that currently exists on Earth.

By Tom Acres, technology reporter

Thursday 27 July 2023 12:45, UK

EMBARGOED TO 1600 WEDNESDAY JULY 26 Undated handout photo issued by the University of Southampton of a Macle twin diamond discovered in Arctic Canada by Tom Gernon. The team of researchers, led by the University of Southampton, have discovered that the breakup of tectonic plates is the main driving force for the generation and eruption of diamond-rich magmas from deep inside the Earth. Diamonds are hundreds of millions or even billions years old and are formed under great pressure. Issue date: W
Image: A Macle twin diamond discovered in Arctic Canada by lead researcher Tom Gernon
Why you can trust Sky News

Scientists have paved the way for future discoveries of rare diamonds after solving why they "erupt" in the Earth's surface.

The prized jewels, which are hundreds of millions or even billions of years old, have long been known to form under great pressure and are typically found in a type of volcanic rock called kimberlite.

But their route to the surface was more of a puzzle - until now.

A team of researchers from the University of Southampton found the driving force is the breakup of tectonic plates.

These huge slabs of rock, which are chunks of the Earth's crust, force the generation and eruption of diamond-rich magmas from deep inside the planet.

Dr Tom Gernon, associate professor of Earth science at Southampton, said the "cyclical" pattern of these diamond eruptions mimicked the rhythm of the supercontinents, which assemble and break up over time.

The most recent supercontinent was Pangaea, which existed about 335 million years ago and was made up of every continent that currently exists on Earth.

EMBARGOED TO 1600 WEDNESDAY JULY 26 Undated handout photo issued by the University of Southampton of heavy machinery operating within a major diamond mine in South Africa. The team of researchers, led by the University of Southampton, have discovered that the breakup of tectonic plates is the main driving force for the generation and eruption of diamond-rich magmas from deep inside the Earth. Diamonds are hundreds of millions or even billions years old and are formed under great pressure. Issue
Image: A major diamond mine in South Africa

Dr Gernon's team, which also included researchers from Birmingham and Leeds universities, used statistical analysis and machine learning - a field of AI where computers are taught to make predictions based on data - to examine the link between continental break-up and kimberlite formations.

Birmingham's Dr Stephen Jones, the study's co-author, compared it to a "domino effect".

The scientists found most kimberlite volcano eruptions happened 20 to 30 million years after Pangaea broke up, gradually migrating from the edges of continents towards the interiors.

Be the first to get Breaking News

Install the Sky News app for free

They then found the Earth's mantle - the layer between the crust and the core - was disrupted by "rifting", when two tectonic plates move away from each other.

This sees chunks of continental crust sink into the mantle below, removing substantial amounts of rock - tens of kilometres thick - from the base of the continental plate.

Dr Gernon said: "This process brings together the necessary ingredients in the right amounts to trigger just enough melting to generate kimberlites."

More on Sky news:
How Oppenheimer changed the world
Stunning image reveals secrets of how giant plants form

EMBARGOED TO 1600 WEDNESDAY JULY 26 Undated handout photo issued by the University of Southampton of a diamond ore rock (kimberlite) showing dark crystals (olivine) and fragments of rock that were formed during explosive volcanic eruptions. The team of researchers, led by the University of Southampton, have discovered that the breakup of tectonic plates is the main driving force for the generation and eruption of diamond-rich magmas from deep inside the Earth. Diamonds are hundreds of millions o
Image: Diamond ore rock (kimberlite) showing dark crystals and fragments of rock formed during volcanic eruptions

The scientists say their findings help them understand the locations and timings of past volcanic eruptions, and therefore how to locate potential diamond deposits.

The study was published in the journal Nature.