The La Garita eruption
The largest single explosive eruption known — five thousand cubic kilometres of rock, thrown out at once.
- When
- Known to
- ± 300 thousand years
- Era
- Oligocene, Cenozoic
The Fish Canyon Tuff, erupted from the La Garita caldera in what is now Colorado around 28 million years ago, has an estimated volume of about 5,000 cubic kilometres, several times the largest Yellowstone eruption and roughly five thousand times Mount St Helens. It is the largest confirmed explosive eruption in Earth's history. Curiously the deposit shows relatively little evidence of climate catastrophe, and the Fish Canyon Tuff has become the standard reference material against which argon-argon dating laboratories worldwide calibrate their results.