Super volcanic eruptions occurred millions of years ago and blanketed North America with ash.
The eruptions were caused by the interaction of the Farallon plate and the North American continental plate.
The thick continental plate prevented the easy outlet of magma, resulting in explosive eruptions.
Animals and plants survived these eruptions by hiding in burrows, underwater, or adapting to the new environment.
The ash deposits from these eruptions created fertile soils and preserved fossils.