Unlocking the Mystery: How Geologists Uncovered the Substance Driving Diamonds to the Earth’s Surface

A recent study in Geology reveals how carbon dioxide plays a key role in bringing diamonds to the Earth’s surface. Led by Ana Anzulović from the University of Oslo, the research dives into the behavior of kimberlite magma, the rare volcanic rock that carries diamonds.

One of the biggest findings is that at least 8.2% carbon dioxide is essential for kimberlite to rise. Without enough CO2, the magma would be denser and would get stuck before reaching the surface. Anzulović emphasizes the importance of this detail in understanding how diamonds travel:

“The most important takeaway from this study is that we managed to constrain the amount of CO2 that you need in the Jericho kimberlite to successfully ascend through the Slave craton.”

To investigate this, the team conducted simulations to see how different mixtures of water and carbon dioxide affect the magma’s buoyancy. They discovered that these gases are vital for keeping the magma moving upward. This knowledge not only improves our understanding of how diamonds are transported but also aids geologists in identifying which kimberlite pipes might contain diamonds, enhancing exploration efforts.

Kimberlite magma is unique because it forms deep in the Earth’s mantle, where it’s extremely hot. It carries various materials, including diamonds, from these depths. The study shows how dissolved gases like water and carbon dioxide impact the movement of the magma. Water lowers viscosity, helping the magma flow, while carbon dioxide strengthens it at greater depths. Together, they allow for quick ascent, preventing diamonds from turning into graphite, a more stable form of carbon found at shallow depths. This rapid ascent traps diamonds within the magma, allowing them to be collected from kimberlite pipes when the magma cools.

The research focused on the Jericho kimberlite pipe in northern Canada, a well-known diamond source located in the Slave craton, one of the oldest parts of the Earth’s crust. By studying this specific area, the team modeled how magma rises and brings diamonds with it. Anzulović notes:

“Our most volatile-rich composition can carry up to 44% of mantle peridotite, for example, to the surface, which is really an impressive number for such a low viscosity melt.”

The presence of carbon dioxide and water varies in kimberlite, which affects how it behaves during its journey to the surface. Understanding these variations can help predict future diamond deposits.

This study not only sheds light on diamond transport but also reveals insights into the geological history of the region. The findings could spark interest in similar studies and further exploration of kimberlite pipes.

Recent data shows that diamond exploration has increased in areas like Canada, with more companies seeking to uncover new sources. As environmental concerns rise, understanding the geological processes behind diamond formation and transport can help in responsible mining practices.

By learning more about how diamonds travel from the depths of the Earth, scientists can refine their exploration methods and improve the chances of finding more of these precious gems. For more information, you can check the detailed study published in Geology.

Source link