Scientists obtain deepest sample of rock from Earth’s mantle

One such place is Atlantis Massif, a submerged mountain where mantle rocks are exposed on the seafloor. It lies in the middle of the Atlantic Ocean, west of the great Mid-Atlantic Ridge, which forms the boundary between the North American, Eurasian and African plates.

Using equipment aboard the JOIDESsolution, researchers drilled into the mantle 850 meters below the ocean surface between April and June 2023. The collected sample contains more than 70% rock and spans 886 meters of the drilled hole.

“The recovery is record-breaking,” said geologist Johan Lissenberg, of Cardiff University and lead author of the study published in the journal Science. “Previous attempts to drill into the mantle have been difficult, with only 200 metres of depth penetrated and relatively low recovery of rock. In contrast, we have chosen 1,268 metres, and we have captured large sections of continuous mantle rock.”

The central sample is about 6.5 cm in diameter.

The scientists placed a reinforced concrete cylinder over the hole, “and then drilling became unexpectedly easy,” said geologist and study co-author Andrew McCaig.

The sample is still being analyzed. Researchers have made some preliminary discoveries about its composition and documented a more extensive melting history—molten rock—than expected.