Black smokers are not found at Lost City. They are are formed when volcanic action emits metal sulfides, while the calcium carbonate white chimneys at Lost City were formed when fluids with a very high pH and calcium content mixed with seawater. This vigorously venting black smoker, called Sully, emits jets of particle-laden fluids that create the "black smoke". The particles are predominantly very fine-grained sulfide minerals formed when the hot hydrothermal fluids mix with near freezing seawater. Image courtesy of University of Washington.