Science Focus Topic 10 Notes: Fossil Fuels | Print |
Petroleum is a naturally occurring mixture of hydrocarbons, such as bitumen, coal, oil and gas.

It is found in sedimentary rock basins, which were formed from the sediments of tiny plants and animals deposited in the mud and silt.

The soft parts of these organisms were transformed into solid, liquid or gas hydrocarbons called
fossil fuels. (Coal is usually formed from plants that grew on the land, oil from water-based plants and animals and natural gas from land-based or water-based plants and animals)

- Another theory suggests that fossil fuels were trapped inside the Earth, at the time of its formation, and have been slowly rising to the surface.

Finding and Mining Fossil Fuels
(Western Canada Sedimentary Basin)

- Surface rock is studied and samples from deep below the surface to identify traps where oil and gas have accumulated within rock formations

Bitumen is a heavy, almost solid form of petroleum. Some deposits can be mined (because they are close to the surface - like, in the Athabasca Tar Sands - sometimes using steam, or hot water to separate the oil and the sand)

- There are three ways that oil and gas can be trapped
(see Figure 5.91, p. 429):

A ? thrust fault

B ? normal fault

C ? reef

WRAP-UP p. 433