Fingerprints of Earth's Original Building Blocks Discovered in Diamond-Bearing Rocks

The research team analyzed kimberlites–a type of rock formed by cooling magma that sometimes carries diamonds–from around the world, including many from Canada.

“We found that kimberlites’ chemical signatures are remarkably uniform and very like the chondritic building blocks thought to have formed the Earth 4.55 billion years ago,” added Pearson, professor in the Department of Earth and Atmospheric Sciences, Henry Marshall Tory Chair, and Canada Excellence Research Chair Laureate. “We think this is the cleanest signal of this primordial signature 

The interior of our planet is constantly cycling, as minerals at Earth’s surface are continually returned to great depths through movement of the tectonic plates. “This mixing makes it very difficult to detect the starting ingredients–a bit like trying to detect the brand of flour that was used by tasting an over-cooked cake,” explained Pearson. “The final twist is that in the last 200 million years, these signatures became more scarce, likely due to events associated with the breakup of the supercontinent, Pangaea.”