A lecture by Prof Marco Fiorentini hosted by the University of Western Australia’s Centre for Exploration Targeting caught my attention. It’s entitled “Sulfur dioxide degassing during Archean and the genesis of komatiite-hosted nickel-sulfide mineralisation”.
Before I describe why I noticed it, let me briefly explain the background behind some terms in the title.
Sulfur dioxide (SO2) is one of the main gases emitted from volcanic eruptions. It’s poisonous with an irritating, pungent, and rotten smell. Inhalation can cause breathing difficulty, disease, and premature death. When released from volcanic eruptions it poses a hazard to people, animals, and vegetation. Local to the eruption it can cause acid rain and air pollution. If large volumes of sulphur dioxide aerosols are injected into the stratosphere it can deplete the earth’s ozone layer and lower surface temperatures. (Volcanic Gases and Their Effects)
Komatiites are submarine lavas that erupted at high temperature (1600°C compared with 1100 to 1250°C for basalt lavas). Thus, they were extremely fluid, and flowed rapidly like water across the surface, compare with basaltic lava, which flows like honey. Komatiite was named after the Komati River in South Africa, which is its type locality.
Like basaltic lava, komatiite lava originated when part of the mantle rock inside the earth melted. The difference between komatiite and basalt is that, because of the higher temperatures involved, a greater proportion (around 50%) of the mantle rock melted producing the komatiite lava. As a result komatiites are rich in magnesium oxide (MgO).
