Flood basalts

Part of Hall of Planet Earth.

Flood Basalts AMNH/R.Mickens

Among the major outpourings of lava are the huge plains known as flood basalt provinces. The Siberian basalts, the Deccan traps of India, and the Karoo basalts of southern Africa are among the largest of these on land; similar vast plains exist in the ocean basins as well. Each province was built up in just a few million years. The enormous amounts of volcanic gases injected into the atmosphere may have led to climate changes that caused global mass extinction events.