In deep sea hydrothermal vents, water heated by Earth’s mantle flows into the ocean, precipitating various minerals, including metal sulfides. These minerals form channels for the vent water, and since the metal sulfides are electrically conductive and the vent and ocean water are compositionally different, an electric current is created. Scientists have shown this current can reduce metal sulfides to metals, which can reduce organic compounds. These reactions could have helped jump-start life’s chemistry.
Source: Science Daily