Natural geologic hazards arise from the interaction between humansс and the Earth’s natural processes. Recent natural disasters such as the 2004 Indian Ocean tsunami that killed more than a quarter million people and earthquakes in Iran, Turkey, and Japan have shown how the motion of the Earth’s tectonic plates can suddenly make apparently safe environments dangerous or even deadly. Th e slow sinking of the land surface along many seashores has made many of the world’s coastal regions prone to damage by ocean storms, as shown disastrously by Hurricane Katrina in 2005.

Grade and tonnage models are useful in quantitative mineral-resource assessments. The models and database presented in this report are an update of earlier publications about volcanogenic massive sulfide (VMS) deposits (Mosier, Singer, and Salem, 1983; Cox, 1986; Singer, 1986a-c; Singer and Mosier, 1986a, b). These VMS deposits include what were formerly classified as kuroko, Cyprus, and Besshi deposits.

Volcanogenic massive sulphide (VMS) deposits are also known as volcanic-associated, volcanic-hosted, and volcano-sedimentary-hosted massive sulphide deposits. They typically occur as lenses of polymetallic massive sulphide that form at or near the seafloor in submarine volcanic environments. They form from metal-enriched fluids associated with seafloor hydrothermal convection. Their immediate host rocks can be either volcanic or sedimentary.