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What Happened?

Massive basalt lava flows erupted in pulses for about 1 million years, covering eastern Siberia.

Ash clouds blocked sunlight, temporarily lowering global temperatures. But the lava flows also burned nearby coal deposits, releasing carbon dioxide and methane. These gasses trapped heat in the atmosphere, raising temperatures and causing acid rain that changed the ocean chemistry.

These changes led to worldwide extinctions, mostly in marine ecosystems.
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