Deepest-ever rock sample obtained from earth's mantle

It gives scientists a glimpse of what the earth looks like beneath its outer crust

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Scientists using an ocean drilling vessel have dug the deepest hole ever in rock from the earth's mantle penetrating 1,268m below the Atlantic seabed and obtained a large sample that is offering clues about the planet's most voluminous layer.

This cylindrical core sample, researchers said on Aug 8, is providing insight into the composition of the upper part of the mantle and the chemical processes that occur when this rock interacts with seawater over a range of temperatures.

Such processes, they said, may have underpinned the advent of life on earth billions of years ago.

The mantle, making up more than 80 per cent of the planet's volume, is a layer of silicate rock sandwiched between the earth's outer crust and a ferociously hot core.

Mantle rocks generally are inaccessible except where they are exposed at locations where the sea floor spreads between the slowly moving continent-size plates that make up the planet's surface.