By Sid Perkins
Hydrocarbons in the fluids spewing from a set of hydrothermal vents on the seafloor of the central Atlantic were produced by inorganic chemical reactions within the ocean crust, scientists suggest. The finding holds possibly profound implications for the origins of life.
The Lost City hydrothermal field, which sits on the side of an undersea mountain about 2,500 kilometers east of Bermuda, was discovered in December 2000 (SN: 7/14/01, p. 21). Unlike most hydrothermal vents, which crop up along midocean ridges where tectonic plates spread to form new seafloor, those of the Lost City lie about 15 km west of the Mid-Atlantic Ridge on ocean crust that’s about 1.5 million years old. Accordingly, the chemistry of the fluids surging from the Lost City vents differs radically from that found at other hydrothermal sites, says Giora Proskurowski, a geochemist at Woods Hole (Mass.) Oceanographic Institution.