Fossil fuels

Cross section of the ocean and ocean bed
Source: Image courtesy of the Paleontological Research Institution

Tens of thousands of years ago when plants and animals died they became buried in mud and sand.

Over time many more layers of mud and sand covered these plants and animals, leaving them buried deep below the earth's surface.

Great pressure and heat caused the mud and sand to change, hardening it into peat and then sedimentary rock. Over thousands and thousands of years, the buried plants and animals turned into fossil fuels.

Types of fossil fuels

Fossil fuels include coal, oil and natural gas.

Because fossil fuels take thousands of years to create and are at risk of running out, we describe them as non-renewable forms of energy.

Stages in the development of coal
Source: Image courtesy of the Australian Coal Association