Unexplained - Earth.com

At the farthest reaches of the Kola Superdeep Borehole, researchers and scientists had measured seismic waves and predicted that the rock underneath Earth’s surface gradually changes from granite to basalt at around two to four miles beneath our feet.

However, experts were blindsided when they learned that this wasn’t the case at all — or at least not on the Kola Peninsula. Photo Credit: Hitchster

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