EXTINCTIONS × EARTH

End-Triassic Mass Extinction

~201 million years ago

Phanerozoic · Mesozoic · Jurassic

Pangaea began to split, and the crack filled with basalt: the Central Atlantic Magmatic Province, one of the largest volcanic events known, erupting in four pulses over about 600,000 years. Bubbles trapped in that basalt show that at least part of its carbon dioxide came from depth, from the mantle or the lower to middle crust, and that each pulse lasted only a few centuries. Marine diversity fell by up to about half, and ecosystems on land were overturned as well.

Why it matters

Each of those pulses put into the air about as much carbon dioxide as human activity is projected to emit across the twenty-first century. That is the comparison to hold on to: the end-Triassic shows what a century of emissions on our scale looks like once the rocks have recorded the outcome. What followed was global warming, ocean acidification, and dinosaurs entering the Jurassic as the dominant land vertebrates.

Dating & uncertainty

Zircon dates tie the extinction to the first pulses of the Central Atlantic Magmatic Province to within about 100,000 years, which is as close as geochronology can currently place cause and effect.

Sources

1. Blackburn et al. (2013), Science · Zircon U-Pb geochronology links the end-Triassic extinction with the Central Atlantic Magmatic Province
2. Ruhl et al. (2011), Science · Atmospheric carbon injection linked to end-Triassic mass extinction
3. Capriolo et al. (2020), Nature Communications · Deep CO2 in the end-Triassic Central Atlantic Magmatic Province
4. Lindström et al. (2021), Earth-Science Reviews · Tracing volcanic emissions from the Central Atlantic Magmatic Province in the sedimentary record

Earth history as one day

22:56:071 h 4 min before midnight

if Earth’s 4.54 billion years were compressed into a single day