hydrothermal vent
A fissure on the floor of a sea out of which flows water that has been heated by underlying magma. The water can be as hot as 400°C (752°F) and usually contains dissolved minerals that precipitate out of it upon contact with the colder seawater, building a stack of minerals, or chimney. Hydrothermal vents form an ecosystem for microbes and animals, such as tube worms, giant clams, and blind shrimp, that can with stand the hostile environment.