fossil fuel

https://doi.org/10.1351/goldbook.F02490
A fuel such as coal, oil and natural gas which has formed over many years through the @D01547@ of deposited vegetation which was under extreme pressure of an overburden of earth.
Source:
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2190 [Terms] [Paper]