Komatiite
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Komatiite is a type of ultramafic mantle-derived volcanic rock defined as having crystallised from a lava of at least 18 wt% magnesium oxide. It is classified as a 'picritic rock'. Komatiites have low
Komatiite lava at the type locality in the Komati Valley, Barberton Mountainland, South Africa, showing the distinctive "spinifex texture" formed by dendritic plates of olivine (scale shown by a hammer on the right edge of photo)
Komatiite sample collected from the Abitibi greenstone belt near Englehart, Ontario, Canada. Specimen is 9 cm wide. Bladed olivine crystals are visible, though spinifex texture is weak or absent in this sample.
Graph of komatiite geochemistry MgO% vs Cr ppm, from basal flows, Wannaway, Western Australia
Photomicrograph of a thin section of komatiite showing spinifex texture of pyroxene needle-like crystals
Geothermal gradient
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Geothermal gradient is the rate of change in temperature with respect to increasing depth in Earth's interior. As a general rule, the crust temperature rises with depth due to the heat flow from the m
Komatiite
…eruption temperatures of about 1100 to 1250 °C. The higher melting temperatures required to produce komatiite have been attributed to the presumed higher geothermal gradients in the Archaean Earth. Komatiitic lava was extremely fluid when it erupted (possessing the viscosity close to that of water but with the density of…
Geothermal drill machine in Wisconsin, US
Nesjavellir Power Plant edit 2