SeaFloor Massive Sulphides (SMS)

Sea-Floor Massive Sulphides (SMS) or Hydrotermal Sulfides are modern equivalents of on-shore (ancient) volcanogenic massive sulphides (VMS) which have constituted important mining targets through history in many regions of Europe. VMS deposits are generally stratiform accumulations of sulphides formed at or just beneath the seafloor as a result of volcano-magmatic activity. The sulphides are precipitated from hot hydrothermal solutions when they come in contact with cold seawater.

 

Deposits of this type that form today are known as seafloor massive sulphides, and the associated sulphurous plumes are called  black and  white smokers.

Figure 1
Figure 1

Loki Castle hydrothermal vent field, located at the Artic Mid-Ocean Ridge. Photo: University of Bergen.

Figure 2
Figure 2

Black smoker located in the 'Moytirra' vent field (North Azores, NE Atlantic Ocean). Photo: Venture Project.

Figure 4
Figure 4

The summit of a hydrothermal vent located in the 'Lucky Strike' vent field. Photo: IFREMER

Figure 1
Figure 1

Loki Castle hydrothermal vent field, located at the Artic Mid-Ocean Ridge. Photo: University of Bergen.

1/5

Data from ancient VMS deposits are essential for the present-day understanding of the formation, structure and composition of SMS deposits. VMS deposits are among the most important deposit types for a number of commodities, including copper (Cu), zinc (Zn), lead (Pb), silver (Ag) and gold (Au).

 

In addition, they may contain economic grades of cobalt (Co), tin (Sn), barium (Ba), sulphur (S), selenium (Se), indium (In), bismuth (Bi), tellurium (Te), gallium (Ga) and germanium (Ge). Several of these minor constituents are considered critical raw materials by the EU. The modern equivalents are found on the ocean floor, along present-day spreading ridges and volcanic centres, and are the target of steadily increasing attention as a possible source for both base, precious and special metals.