In some cases, the dead plants don’t become rocks. Under immense heat and pressure, they turn into fossil fuel. Oil and gas come from plants in the Ocean and coal from swamps.
All of this happened 300 million years ago, way before dinosaurs walked around.
A big eruption like that of Mt. St. Helens only happens every 12 years.
By burning fossil fuels, we have brought ancient carbon of the ultra-slow cycle into the fast cycle. So... how much faster are we?
Mt. St. Helens
Humans in 1 year
4600 x 10,000,000 t