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 1960s. 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 consist 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 greatest 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...
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