Researchers have drilled the deepest-ever sample of rocks from Earth's mantle, penetrating 0.7 mile (1.2 kilometers) in the Mid-Atlantic Ridge, where the seafloor is spreading apart.
At this spot, which is rich in hydrothermal vents, the interactions between mantle rocks and seawater create chemicals that are important for life. Previous efforts to drill into mantle rocks brought to the surface in the deep sea had reached only 659 feet (201 meters) — not deep enough to look for organisms such as heat-loving bacteria that might dwell farther down, said Gordon Southam, a geomicrobiologist at the University of Queensland in Australia and a co-author of a new study describing the core sample.
