'Seafloor massive sulfide deposits' or SMS deposits, are modern equivalents of ancient
volcanogenic massive sulfide ore deposits or VMS deposits. The term has been coined by mineral explorers to differentiate the modern deposit from the ancient.
SMS deposits were first recognised during the exploration of the deep oceans and the
mid ocean ridge spreading centers in the early 1960's. Deep ocean
bathyspheres and remote operated vehicles have visited and taken samples of
black smoker chimneys, and it has been long recognised that such chimneys contain appreciable grades of Cu, Pb, Zn, Ag, Au and other trace metals.
SMS deposits are currently forming in the deep ocean around submarine volcanic arcs, where
hydrothermal vents exhale sulfide-rich mineralising fluids into the ocean.
SMS deposits are laterally extensive and are comprised of a central vent mound around the area where the hydrothermal circulation exits, with a wide apron of unconsolidated sulfide silt or ooze which precipitates upon the seafloor.
Economic importance
Economic extraction of SMS deposits is in the theoretical stage, the biggest complication being the extreme water depths at which these deposits are forming. However, apparent vast areas of the peripheral areas of these black smoker zones contain a sulfide ooze which could, theoretically, be vacuumed up off the seafloor.
Known SMS deposits
Deep ocean drilling, seismic
bathymetry surveys and mineral exploration deep sea drilling has delineated several areas worldwide with potentially economically viable SMS deposits, including:
★ Kermadec Volcanic Arc
★ Colville Ridge
See also
★
Hydrothermal circulation
★
Mid ocean ridge
★
Ore genesis
References
★
''The dawn of deep ocean mining'', Steven Scott, Feb. 2006
★
Neptune Minerals
★
Nautilus Minerals