Exploration & Mining Glossary

VMS - Layered deposits containing varying amounts of pyrite, copper, lead and zinc sulphide minerals, along with baryte. Commonly, also gold and silver. VMS deposits form when hot fluids circulate through rocks of the seafloor, dissolving various metals, and then come into contact with cold seawater, causing the metals to precipitate as piles of tiny mineral grains. VMS ores are often located near “black smokers”, jets of superheated water shooting from the ocean floor. Some ancient VMS deposits are today found on continents or islands, having been lifted from the seafloor by tectonic action.

Volcanic rocks - Igneous rocks formed from magma that has flowed out or has been violently ejected from a volcano.

Volcaniclastic sediments - All clastic sediments composed mainly of particles of volcanic origin, regardless of how the sediment formed.

Volcanogenic Massive Sulphide (VMS) / Volcanic-hosted Massive Sulphide (VHMS) - Layered deposits formed when hot, sulphide laden fluids erupt through fractures in the sea floor. These are typically an important source of zinc, copper & lead.