Bling Fling: Eruptions of Diamonds May Have Blasted Gem-Rich Magma from Earth's Depths

Explosive eruptions from deep within the Earth's mantle, triggered by the breakup of supercontinents, could propel diamonds to the surface, potentially revolutionizing the way precious stones are sought, according to researchers.

A recent study by an international team of scientists published in the journal Nature digs into the phenomenon of diamond-rich magma, known as "kimberlites," originating from depths up to 100 miles beneath the Earth's surface. These magmas have explosively erupted in the planet's geological history.

Kimberlites are commonly found in the oldest and thickest parts of continents, such as the Venetia Diamond Mine in South Africa, which witnessed a diamond rush in the late 1800s. However, the mechanisms by which these valuable gemstones reach the Earth's surface in such locations have long perplexed scientists.

Lead researcher Thomas Gernon, a professor of Earth and climate science at the University of Southampton in England, notes that the pattern of diamond eruptions corresponds to the cyclical rhythm of supercontinents assembling and breaking up over time.

The research team utilized statistical analysis to examine formations over the past billion years, revealing a consistent relationship between continental breakup and kimberlite volcanism. Most kimberlites erupted approximately 30 million years after continental breakup, indicating an association with the processes of rifting.

Further investigation uncovered a connection between the Earth's tectonic breakup and the diamond-rich magma.

Geospatial analysis demonstrated that kimberlite eruptions gradually migrate from continental edges to interiors over time, maintaining consistent rates across continents.

Describing the process as a "domino effect," researcher Stephen Jones from the University of Birmingham explained that during the stretching of plates, a portion of the continental root breaks and sinks into the mantle below, initiating a chain reaction of similar flow patterns under the nearby continent.

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Simulations of this process by the research team aligned with observations in kimberlite records. Gernon emphasized that this process brings together the necessary components to generate sufficient melting for the creation of kimberlites.

In addition to offering insights into the timing and locations of past volcanic eruptions, the research may aid future searches for diamond deposits.

Gernon suggested that the breakup not only reorganizes the mantle but could also profoundly impact the Earth's surface environment and climate, emphasizing that diamonds might only be a part of the larger story.