Diamond Discovery Offers New Understanding of Earth’s Geological Processes

A recent paper published in the journal Nature points to a “superdeep” diamond recovered in Kankan, Guinea, as the messenger of new information about plate tectonics, the geological processes that give rise to mountains, oceans and continents.

The purity of the olivine, as well as some of the other minerals that were inclusions in the precious rock, indicate a much deeper origin than usual for a diamond, between what is called the transition zone and the lower zone. of the mantle – 420 kilometers to 660 kilometers below the surface of the earth. It also shows that the environment between these zones has an extremely variable oxygen content.

“To create this extreme [olivine] composition and overall mineral assemblage that we have, the only way to do that is to have a very deeply subducted oceanic plate or slab that goes down into the mantle, so you’re basically pushing materials from the surface of the earth into the depths of the earth,” said Graham Pearson, co-author of the study and director of the Diamond Exploration and Research Training School at the University of Alberta, in a Press release.

Most other minerals lose much of this information the moment they rise to the surface, but, as Pearson explained, diamonds act almost like time capsules.

“There are a lot of things on the surface of the earth that can only be explained by processes going on deep down,” he pointed out. “If you want to explain what you see on the surface, whether it’s economic mineralization, surface uplift, or subsidence phenomena related to oilfields, you need to understand the structure, mechanics, and properties of deep earth. Diamond is the only one capable of reinforcing this understanding.