“A record-breaking expedition to drill into rocks at the bottom of the Atlantic Ocean has given scientists their best glimpse yet of what the Earth might look like underneath its crust.

Researchers extracted an almost uninterrupted 1,268-metre long sample of green-marble-like rock from a region where Earth’s mantle — the thick, interior layer that makes up more than 80% of the planet’s bulk — has pushed up through the sea floor (see ‘Deep-sea drilling’). The samples, described on 8 August in Science, offer unprecedented insights into processes that lead to the crust’s formation.”

From Nature.