Metal sulfides, iron-manganese oxides. hydroxides and iron silicates from rising vent fluid precipitate in seawater forming white and black"smoke Direction of bottom current …∷… Riftia tube Copper- iron-zinc sulfides worms precipitate inside vent and chimney Seawater seeps through cracks and fissures in crust Seafloor Fractured Fractured Basalt Basalt From crust seawater Silicon Magma heating seafloor Basic Structure of a hydrothermal vent with its Mutualistic microbe-Animal associationsBasic Structure of a Hydrothermal Vent with its Mutualistic Microbe-Animal Associations