volcanogenic massive sulfide

Volcanogenic massive sulfide (VMS) deposits are a type of hydrothermal mineral deposit formed by submarine volcanic activity. When seawater seeps into volcanic rocks and is heated by magma, it forms a hydrothermal solution that concentrates scarce metals. This superheated, metal-rich fluid then erupts onto the seafloor as a hot spring, rapidly cooling and depositing its dissolved load as massive sulfide minerals.1

These deposits are significant sources of copper, lead, and zinc, and can also contain gold and silver. Famous examples include the kuroko deposits in Japan, the historic copper deposits of Cyprus, and deposits in Canada like Kidd Creek and Noranda. VMS deposits are found in ancient seafloor rocks and are still forming today along mid-ocean ridges and in back-arc basins.1