The process of coal formation is still taking place today, says Bailey. “The precursor to coal is called peat, and that is just uncompressed plant matter.” Peat accumulates in wet swampy environments known as mires, and that process is taking place today in areas such as Indonesia and even the Antiplano in the Andes.

When did coal stop forming?

About 300 million years ago, mushrooms and other fungi developed this ability, ending the main coal-formation period of earth’s history.

Are fossil fuels still being created?

This process can happen surprisingly quickly, geologically speaking. A lot of the action described above is ongoing, and has only recently generated some oil and gas fields, in basins like the Gulf of Mexico and the Caspian Sea. You could get your first new accumulations in as little as a couple of million years.