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Earth Evolution
Earth Materials
Earth Evolution
Geological History
Solar System
Archean Proterozoic Early
Late Paleozoic Mesozoic Cenozoic

Archean Beginnings 3800-2500 Ma
Origin of the Earth’s Crusts

Much of the Earth’s earliest primitive crust was made of komatiites that represent the first oceanic crust on our planet. Komatiites are ultramafic rocks with high magnesium and chromium contents which formed above mantle hot spots at temperatures of up to 1650ºC, much hotter than any lavas erupting on Earth today (1100ºC).