They are formed by natural processes like anærobic decomposition. They contain energy from ancient photosynthesis. They can literally be around 650 million years old.
fossil fuels formed from the decayed of plants and animals through a natural processes.
Explanation:
Fossil fuel is formed over millions of years when the remains of plants and animals are buried within the earth's crust and when subjected to high pressure and heat that have been converted into fossil fuel.
Nonrenewable resource: it cannot be renewed, once they are consumed.
Fossil fuel is an example of nonrenewable source, as they there form from the decay of animals and plants that have lived over millions of year ago and once they are consumed it cannot be renewed.