Until Now
GeologyDisasterEnvironment

Volcanism in the extinction record

Mercury anomalies point to massive eruptions alongside the ice as a cause of the dying.

When
Known to
± 2 million years
Era
Ordovician, Paleozoic

Sedimentary mercury spikes, a fingerprint of large igneous province volcanism, occur at both pulses of the Late Ordovician extinction, though with different chemical signatures. This has revived the argument that eruptions contributed alongside glaciation and anoxia. The Late Ordovician remains the one major mass extinction traditionally attributed to cooling rather than volcanic warming, and that consensus is now under pressure.

Just before

Just after