Above your head, the flanges trap reflecting pools of water. They make perfect mirror planes and look like upside-down water falls. Until now, ocean scientists believed they had seen all that seafloor vents had to offer in previous expeditions. But the Lost City contains scientific surprises, besides a stunning appearance. For starters, researchers said, it occurs on a piece of Earth's crust that is about 1 million years old.
Most vents occur at points where the crust is much younger.
The water from the vents is relatively cool at 160 degrees. The structures are composed of carbonate minerals and silica. Most seafloor hot springs deposits are formed by iron and sulfur-based minerals. Rocks in the rugged area were formed in Earth's hot mantle and pushed several miles up to the seafloor along active faults. Unlike vents in the Pacific, the mid-Atlantic vent field shows relatively little complex life.