English: This is a cross-section of a typical volcanogenic massive sulfide (VMS) ore deposit. An exhalite or tuffite is composed of sediment deposited out of seawater influenced by vented hydrothermal fluids. An exhalite horizon on the paleoseafloor can usually be followed along strike to its source vent, which is useful for exploration. The underlying older volcanic rocks are not the direct source of mineralization.