The Ethiopian flood basalts
A plume head reaches the surface under Africa and erupts a kilometre-thick basalt pile in a million years or less.
- When
- —
- Duration
- 1.5 million years
- Known to
- ± 500 thousand years
- Era
- Oligocene, Cenozoic
Around 30 million years ago the Afar plume arrives beneath the Ethiopian lithosphere and floods the region with basalt and giant ignimbrites, building a plateau up to two kilometres thick over an area larger than France, most of it emplaced within a million years. The eruption coincides with global cooling, a major Antarctic ice advance and the largest Tertiary sea-level fall, which has prompted repeated attempts to connect them. Its more certain legacy is structural: the plume domes and weakens the crust, and the continent begins to come apart above it.