Volcanogenic-massive sulphide (VMS) deposits · Classes of Ridges Fast-Spreading Mid-Ocean Ridge Fast-spreading ridges, like the East Pacific Rise, the spreading rate is 100 to 200

Volcanogenic-massive sulphide (VMS) deposits

Mineralization type: predominantly stratiform accumulations of sulfide minerals precipitated from hydrothermal fluids at or below the sea floor

Age: from >3.5 Ga till modern geological settings Main commodities: Cu, Zn, ±Pb, Au, and Ag oresMain ore minerals: chalcopyrite, sphalerite, (galena)Gangue minerals: quartz, bariteBy-products: Co, Sn, Ba, S, Se, Mn, Cd, In, Bi, Te, Ga, and Ge

Conceptual diagram illustrating the fluid characteristics and circulation pattern inmid-ocean ridge environments that give rise to the formation of black smokers onthe sea floor (after Lydon 1988; Scott, 1997).

Section through a typical ophiolite-hosted VMS deposit.

vs.

Recent hydrothermal vents – a modern analogue for VMS deposit formation