Until Now
Geology

The great mantle plume event

Superheated plumes rise from the deep mantle and resurface much of the planet in lava.

When
Known to
± 50 million years
Era
Neoarchean, Archean

Around 2.7 billion years ago Earth undergoes a worldwide pulse of igneous activity, producing komatiites — lavas so magnesium-rich they require mantle temperatures far above anything possible today. Komatiite eruption peaks in the Neoarchean and essentially ceases afterwards, making it a direct measure of a cooling planet. The pulse drives crustal growth, ore formation and, indirectly, the chemistry that follows.

Just before

Just after