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Fossil
Fuels: Millions of Years in the Making
Fossil fuels get
their name from the organisms that created them. Fossil fuels were formed
from plants and animals that lived hundreds of millions of years ago.
Around 300 million years ago the earth was covered by giant seas and the
continents were just forming. All sorts of organisms were alive: trees,
plants, land animals, fish, and (one-celled organisms).
The climate was warmer and swamps and bogs were everywhere. When these
organisms died, they were covered up by layers of mud, rock, sand, and
in some cases water. Sometimes thousands of feet of earth buried these
fossils. Over the next many millions of years, the plants and animals
decomposed into fossil fuels. The type of fuel the organisms became depended
on several factors:
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Who
they were buried with. |
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How
long they were buried. |
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What
temperature and pressure existed while they were decomposing. |
Oil and Natural
Gas
Sea life is the source of oil
and natural gas. These organisms died and were buried in ocean and river
sediment. The ancient oceans and rivers dried up and over time new oceans
and rivers covered the old waterbeds. Meanwhile, the protoplankton decayed
and pressure and heat combined with bacteria to cook the organisms. This
produced a thick oil. In hotter regions the cooking process continued
for longer and natural gas formed.
Coal
Coal was formed by the same
sorts of pressure and temperature as oil and natural gas, but coal comes
from the remains of ferns (a much more widely spread species 300 to 380
million years ago), trees, and other plants.
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