Mantle rock

For a long time I’ve taught about the Kola Superdeep Borehole, the farthest humans have dug into the Earth’s crust. While getting 12,262 m deep, it never broke through to the mantle.

Now, scientists have gotten core samples from the mantle, without having to beat the Kola borehole. By digging along the Mid Atlantic Ridge, they were able to pull rocks from the upper mantle from a “tectonic window” where the mantle is very near the surface (of the Earth, not the ocean).